JPWO2006046397A1 - Substrate for thin film photoelectric conversion device and integrated thin film photoelectric conversion device using the same - Google Patents

Substrate for thin film photoelectric conversion device and integrated thin film photoelectric conversion device using the same Download PDF

Info

Publication number
JPWO2006046397A1
JPWO2006046397A1 JP2006542332A JP2006542332A JPWO2006046397A1 JP WO2006046397 A1 JPWO2006046397 A1 JP WO2006046397A1 JP 2006542332 A JP2006542332 A JP 2006542332A JP 2006542332 A JP2006542332 A JP 2006542332A JP WO2006046397 A1 JPWO2006046397 A1 JP WO2006046397A1
Authority
JP
Japan
Prior art keywords
photoelectric conversion
thin film
conversion device
substrate
film photoelectric
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2006542332A
Other languages
Japanese (ja)
Inventor
裕子 多和田
裕子 多和田
山本　憲治
憲治 山本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kaneka Corp
Original Assignee
Kaneka Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kaneka Corp filed Critical Kaneka Corp
Publication of JPWO2006046397A1 publication Critical patent/JPWO2006046397A1/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022466—Electrodes made of transparent conductive layers, e.g. TCO, ITO layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022466—Electrodes made of transparent conductive layers, e.g. TCO, ITO layers
    • H01L31/022483—Electrodes made of transparent conductive layers, e.g. TCO, ITO layers composed of zinc oxide [ZnO]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0236—Special surface textures
    • H01L31/02363—Special surface textures of the semiconductor body itself, e.g. textured active layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0236—Special surface textures
    • H01L31/02366—Special surface textures of the substrate or of a layer on the substrate, e.g. textured ITO/glass substrate or superstrate, textured polymer layer on glass substrate
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
    • H01L31/036—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
    • H01L31/0392—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Photovoltaic Devices (AREA)

Abstract

本発明は、ガラス基板等の透光性絶縁基板上に酸化亜鉛を透明電極層として形成した薄膜光電変換装置用基板の光線透過率を改善すること、そしてその基板を用い薄膜光電変換装置の光電変換効率を向上させること、を課題としている。本発明の薄膜光電変換装置用基板は、透光性絶縁基板とその上に堆積された中間層および少なくとも酸化亜鉛を含む透明電極層を有し、中間層内の屈折率が透光性絶縁基板側から透明電極層側に向かって滑らかに変化し、かつ中間層は透明電極層側の界面に凸部が曲面からなる表面凹凸を有することを特徴としており、薄膜光電変換装置用基板の光線透過率が改善され、この基板を用いた薄膜光電変換装置の光電変換効率は向上する。The present invention improves the light transmittance of a substrate for a thin film photoelectric conversion device in which zinc oxide is formed as a transparent electrode layer on a translucent insulating substrate such as a glass substrate, and the photoelectric conversion of the thin film photoelectric conversion device using the substrate. The problem is to improve the conversion efficiency. The thin film photoelectric conversion device substrate of the present invention has a translucent insulating substrate, an intermediate layer deposited thereon, and a transparent electrode layer containing at least zinc oxide, and the refractive index in the intermediate layer is a translucent insulating substrate It changes smoothly from the transparent electrode layer side to the transparent electrode layer side, and the intermediate layer has surface irregularities with convex surfaces at the interface on the transparent electrode layer side, and the light transmission of the substrate for the thin film photoelectric conversion device The rate is improved, and the photoelectric conversion efficiency of the thin film photoelectric conversion device using this substrate is improved.

Description

本発明は、薄膜光電変換装置用基板およびそれを用いた集積型薄膜光電変換装置の性能改善に関する。   The present invention relates to a substrate for a thin film photoelectric conversion device and an improvement in performance of an integrated thin film photoelectric conversion device using the same.

近年、太陽電池を含む光電変換装置の低コスト化、高効率化を両立するために原材料が少なくてすむ薄膜光電変換装置が注目され、開発が精力的に行われている。特に、ガラス等の安価な基板上に低温プロセスを用いて良質の半導体層を形成する方法が低コストを実現可能な方法として期待されている。   In recent years, a thin film photoelectric conversion device that requires less raw materials in order to achieve both cost reduction and high efficiency of a photoelectric conversion device including a solar cell has attracted attention and has been vigorously developed. In particular, a method of forming a high-quality semiconductor layer on an inexpensive substrate such as glass using a low-temperature process is expected as a method capable of realizing low cost.

このような薄膜光電変換装置は、一般に絶縁透光性基板上に順に積層された透明電極層と、１つ以上の光電変換ユニットと、及び裏面電極層とを含んでいる。ここで、光電変換ユニットは一般にｐ型層、ｉ型層、及びｎ型層がこの順、またはその逆順に積層されてなり、その主要部を占めるｉ型の光電変換層が非晶質のものは非晶質光電変換ユニットと呼ばれ、ｉ型層が結晶質のものは結晶質光電変換ユニットと呼ばれている。   Such a thin film photoelectric conversion device generally includes a transparent electrode layer, one or more photoelectric conversion units, and a back electrode layer that are sequentially stacked on an insulating translucent substrate. Here, the photoelectric conversion unit generally has a p-type layer, an i-type layer, and an n-type layer laminated in this order or vice versa, and the i-type photoelectric conversion layer occupying the main part is amorphous. Is called an amorphous photoelectric conversion unit, and those having an i-type layer crystalline are called crystalline photoelectric conversion units.

薄膜光電変換装置は、従来のバルクの単結晶や多結晶シリコンを使用した光電変換装置に比べて光電変換ユニットを薄くすることが可能であるが、反面、薄膜全体の光吸収が膜厚によって制限されてしまうという問題がある。そこで、光電変換層を含む光電変換ユニットに入射した光をより有効に利用するために、光電変換ユニットに接する透明電極層の表面を凹凸化（テクスチャ化）し、その界面で光を散乱した後、光電変換ユニット内へ入射させることで光路長を延長せしめ、光電変換ユニット内での光吸収量を増加させる工夫がなされている。この技術は「光閉じ込め」と呼ばれており、高い光電変換効率を有する薄膜光電変換装置を実用化する上で、重要な要素技術となっている。   The thin film photoelectric conversion device can make the photoelectric conversion unit thinner than the conventional photoelectric conversion device using bulk single crystal or polycrystalline silicon, but the light absorption of the entire thin film is limited by the film thickness. There is a problem of being done. Therefore, in order to use light incident on the photoelectric conversion unit including the photoelectric conversion layer more effectively, the surface of the transparent electrode layer in contact with the photoelectric conversion unit is made uneven (textured) and light is scattered at the interface. The optical path length is extended by making it enter into the photoelectric conversion unit, and the device which makes the light absorption amount in a photoelectric conversion unit increase is made | formed. This technique is called “optical confinement”, and is an important elemental technique for practical use of a thin film photoelectric conversion device having high photoelectric conversion efficiency.

薄膜光電変換装置の一例である非晶質シリコン光電変換装置は、ガラス等の透明絶縁基板上に形成され、透明電極層として表面凹凸を有する酸化錫（ＳｎＯ2）膜が一般的に用いられている。この透明電極層の表面凹凸は、光電変換ユニット内への光閉じ込めに有効に寄与している。しかし、光閉じ込めに有効な表面凹凸を有する透明電極層として熱化学気相堆積法（熱ＣＶＤ法）によりＳｎＯ2膜を形成したガラス基板は、その透明電極層を形成するために約５５０〜６５０℃の高温プロセスを必要とするのでコストが高いという問題がある。また、ＳｎＯ2膜は耐プラズマ性が低く、水素を使用した大きなプラズマ密度での光電変換ユニットの堆積環境下では、ＳｎＯ2膜が還元されてしまう。ＳｎＯ2膜が還元されると黒化し、黒化した透明電極層部分で入射光が吸収され、光電変換ユニットへの透過光量が減少し、変換効率の低下を招く原因となる。An amorphous silicon photoelectric conversion device, which is an example of a thin film photoelectric conversion device, is generally formed of a tin oxide (SnO 2 ) film formed on a transparent insulating substrate such as glass and having a surface asperity as a transparent electrode layer. Yes. The surface unevenness of the transparent electrode layer effectively contributes to light confinement in the photoelectric conversion unit. However, a glass substrate on which a SnO 2 film is formed by a thermal chemical vapor deposition method (thermal CVD method) as a transparent electrode layer having surface irregularities effective for light confinement is about 550 to 650 in order to form the transparent electrode layer. Since a high temperature process at ℃ is required, there is a problem that the cost is high. Further, the SnO 2 film has low plasma resistance, and the SnO 2 film is reduced in the deposition environment of the photoelectric conversion unit with a large plasma density using hydrogen. When the SnO 2 film is reduced, it is blackened, and incident light is absorbed by the blackened transparent electrode layer portion, and the amount of light transmitted to the photoelectric conversion unit is reduced, which causes a decrease in conversion efficiency.

一方、酸化亜鉛（ＺｎＯ）は、透明電極層材料として広く用いられているＳｎＯ2あるいは酸化インジウム錫（ＩＴＯ）よりも安価であり、また耐プラズマ性が高いという利点を有しており、薄膜光電変換装置用透明電極層材料として好適である。特に、非晶質シリコンの形成時に用いられる堆積条件よりも多量の水素を使用し、かつ大きなプラズマ密度を必要とする薄膜多結晶シリコンや微結晶シリコンのような結晶質シリコンを光電変換ユニットの一部としてとして用いた結晶質シリコン薄膜光電変換装置に有効である。On the other hand, zinc oxide (ZnO) has advantages that it is cheaper than SnO 2 or indium tin oxide (ITO) widely used as a transparent electrode layer material, and has high plasma resistance, and is thin film photoelectric. It is suitable as a transparent electrode layer material for a conversion device. In particular, crystalline silicon such as thin-film polycrystalline silicon or microcrystalline silicon that uses a larger amount of hydrogen than the deposition conditions used when forming amorphous silicon and requires a large plasma density is used as one of the photoelectric conversion units. It is effective for a crystalline silicon thin film photoelectric conversion device used as a part.

なお、本願明細書における、「結晶質」、「微結晶」の用語は、部分的に非晶質を含んでいるものも含んでいるものとする。   In the specification of the present application, the terms “crystalline” and “microcrystal” include those partially including amorphous.

例えば、特許文献１に開示されているＺｎＯ膜の形成方法は、２００℃以下の低温有機金属ＣＶＤ法（低温ＭＯＣＶＤ法）ゆえ、熱ＣＶＤ法に比べて低温で凹凸を有する薄膜が形成でき、スパッタ法に比べて１桁以上速い製膜速度にて製膜が可能であり、原料の利用効率も高いことから、薄膜光電変換装置の透明電極層の形成方法として好ましい。従って、薄膜結晶質光電変換装置の光電変換効率を高めるために、特許文献１に開示されているような低温形成ＺｎＯを用い、その表面凹凸形状による光閉じ込め効果を利用した薄膜光電変換装置の高効率化が検討されている。   For example, since the ZnO film forming method disclosed in Patent Document 1 is a low-temperature metalorganic CVD method (low-temperature MOCVD method) of 200 ° C. or lower, a thin film having projections and depressions can be formed at a lower temperature than the thermal CVD method. The film can be formed at a film formation speed one digit or more faster than that of the method, and the utilization efficiency of the raw material is high. Therefore, in order to increase the photoelectric conversion efficiency of the thin-film crystalline photoelectric conversion device, the low-temperature formed ZnO as disclosed in Patent Document 1 is used, and the high-performance of the thin-film photoelectric conversion device using the light confinement effect due to the surface irregularity shape is used. Efficiency is being considered.

さらに、透明電極層を備えたガラス基板を含む光電変換装置用基板は、光電変換装置において光入射側に用いられるため、光閉じ込め効果に寄与する透明電極層の表面凹凸形状に加えて、高い光線透過率が望まれている。特許文献２には、透明電極層に用いられる透明電極層自体の改善だけでは限界がみられた太陽電池を含む光電変換装置の光電変換効率を向上させるために、ガラスと透明電極層との間に高屈折率膜および低屈折率膜の２つの膜を形成した構成を採用した光電変換装置用基板が開示されている。   Furthermore, since the substrate for a photoelectric conversion device including a glass substrate provided with a transparent electrode layer is used on the light incident side in the photoelectric conversion device, in addition to the uneven surface shape of the transparent electrode layer contributing to the light confinement effect, a high light beam Transmittance is desired. In Patent Document 2, in order to improve the photoelectric conversion efficiency of a photoelectric conversion device including a solar cell in which there is a limit only by improving the transparent electrode layer itself used for the transparent electrode layer, between the glass and the transparent electrode layer is disclosed. Discloses a substrate for a photoelectric conversion device employing a configuration in which two films of a high refractive index film and a low refractive index film are formed.

具体的には、５７０℃までガラス基板を加熱した後、熱ＣＶＤ法にてガラス基板側から順に厚さが２８ｎｍのＳｎＯ2膜と２４ｎｍの酸化珪素（ＳｉＯ2）膜を形成し、さらにこれらの上に透明電極層として厚さが６２０ｎｍのフッ素ドープしたＳｎＯ2膜を形成した膜構成が開示されている。上記公報では、ガラス成形時の熱エネルギーを透明電極層形成に利用できる点から、透明電極層にＳｎＯ2膜を適用しており、ガラスと透明電極層との間の多層膜とその上に形成される透明電極層の形成に約５７０℃以上の高温プロセスを用いている。
特開２０００−２５２５０１号公報 特開２００１−０３６１１７号公報 Specifically, after heating the glass substrate to 570 ° C., a 28 nm thick SnO 2 film and a 24 nm silicon oxide (SiO 2 ) film are formed in order from the glass substrate side by a thermal CVD method. A film configuration is disclosed in which a fluorine-doped SnO 2 film having a thickness of 620 nm is formed thereon as a transparent electrode layer. In the above publication, the SnO 2 film is applied to the transparent electrode layer because the thermal energy at the time of glass molding can be used for forming the transparent electrode layer, and the multilayer film between the glass and the transparent electrode layer is formed on the film. A high temperature process of about 570 ° C. or higher is used to form the transparent electrode layer.
JP 2000-252501 A JP 2001-0361117 A

ガラス基板等の透光性絶縁基板上に透明電極層を形成した薄膜光電変換装置用基板において、低コストと高効率を両立させるためには、低温形成可能な点および耐プラズマ性が高いという点から、透明電極層に表面凹凸を有するＺｎＯを用いることが期待される。また、特許文献２よりガラス基板と透明電極層との間の反射損失低減構造が薄膜光電変換装置の光電変換効率改善に有効であることがわかる。従って、ＺｎＯを透明電極層に用いた薄膜光電変換装置用基板において、ガラスと透明電極層との間に反射損失低減構造を設ける検討は光電変換効率向上に繋がる技術として重要であり、さらには簡便な方法が求められる。   In a thin film photoelectric conversion device substrate in which a transparent electrode layer is formed on a translucent insulating substrate such as a glass substrate, in order to achieve both low cost and high efficiency, it can be formed at low temperature and has high plasma resistance. Therefore, it is expected to use ZnO having surface irregularities in the transparent electrode layer. Further, Patent Document 2 shows that the reflection loss reduction structure between the glass substrate and the transparent electrode layer is effective for improving the photoelectric conversion efficiency of the thin film photoelectric conversion device. Therefore, in a substrate for a thin film photoelectric conversion device using ZnO as a transparent electrode layer, it is important to provide a reflection loss reduction structure between the glass and the transparent electrode layer as a technology that leads to an improvement in photoelectric conversion efficiency. Is needed.

そこで、本発明は、ガラス基板等の透光性絶縁基板と低温で形成できるＺｎＯを透明電極層に用いた薄膜光電変換装置用基板の光線透過率を改善し、薄膜光電変換装置の光電変換効率を向上させることを目的としている。   Therefore, the present invention improves the light transmittance of a substrate for a thin film photoelectric conversion device using ZnO that can be formed at a low temperature and a light transmissive insulating substrate such as a glass substrate, and the photoelectric conversion efficiency of the thin film photoelectric conversion device. It aims to improve.

上記課題を解決するために、本発明の薄膜光電変換装置用基板は、透光性絶縁基板とその上に堆積された中間層および少なくとも酸化亜鉛を含む透明電極層を有し、該中間層内の屈折率が該透光性絶縁基板側から該透明電極層側に向かって滑らかに変化し、かつ該中間層は該透明電極層側の界面に凸部が曲面からなる表面凹凸を有することを特徴としている。   In order to solve the above problems, a substrate for a thin film photoelectric conversion device according to the present invention has a light-transmitting insulating substrate, an intermediate layer deposited thereon, and a transparent electrode layer containing at least zinc oxide, The refractive index of the transparent layer changes smoothly from the translucent insulating substrate side toward the transparent electrode layer side, and the intermediate layer has a surface irregularity having a convex surface at the interface on the transparent electrode layer side. It is a feature.

特に、上記中間層が屈折率が１．８〜２．６の高屈折率粒子と屈折率が１．４〜１．７の低屈折率粒子を含むようにすると、高屈折粒子と低屈折粒子の配合を調整することにより、透光性絶縁基板側から透明電極層側に向かって中間層の屈折率を効果的に変化させることができる。さらに、上記中間層に含まれる高屈折率粒子の粒径は低屈折率粒子の粒径よりも小さく、低屈折率粒子の粒径の１／４〜３／４であることが好ましい。 なぜなら、粒径を小さくすることにより、中間層内で高屈折粒子を透光性絶縁基板側に偏積させることができ、屈折率の勾配を効果的に形成できるからである。   In particular, when the intermediate layer includes high refractive index particles having a refractive index of 1.8 to 2.6 and low refractive index particles having a refractive index of 1.4 to 1.7, the high refractive particles and the low refractive particles are used. The refractive index of the intermediate layer can be effectively changed from the light-transmitting insulating substrate side to the transparent electrode layer side by adjusting the blending of. Furthermore, the particle diameter of the high refractive index particles contained in the intermediate layer is preferably smaller than the particle diameter of the low refractive index particles and is ¼ to ¾ of the particle diameter of the low refractive index particles. This is because, by reducing the particle size, highly refracting particles can be accumulated on the translucent insulating substrate side in the intermediate layer, and a refractive index gradient can be effectively formed.

また、前記中間層の平均膜厚としては５０〜２００ｎｍの範囲であることが好ましい。   Moreover, it is preferable that it is the range of 50-200 nm as an average film thickness of the said intermediate | middle layer.

さらに、上記透明電極層が０．７μｍ以上の膜厚を有する場合、透明電極層の内部応力の増加によって透光性絶縁基板から透明電極層の剥がれが懸念されるが、該中間層の表面凹凸によるアンカー効果によって膜剥がれを抑制できるため、特に好ましい。   Further, when the transparent electrode layer has a thickness of 0.7 μm or more, there is a concern that the transparent electrode layer may be peeled off from the translucent insulating substrate due to an increase in internal stress of the transparent electrode layer. It is particularly preferable because peeling of the film can be suppressed by the anchor effect.

また、本発明に係る集積型薄膜光電変換装置は、上記薄膜光電変換装置用基板上に、少なくとも一つの光電変換ユニット、および裏面電極層が複数の光電変換セルを形成するように複数の分離溝によって分離されていて、かつそれらの複数のセルが接続用溝を介して互いに電気的に直列接続されていることを特徴としている。   Further, the integrated thin film photoelectric conversion device according to the present invention has a plurality of separation grooves on the substrate for the thin film photoelectric conversion device so that at least one photoelectric conversion unit and a back electrode layer form a plurality of photoelectric conversion cells. And the plurality of cells are electrically connected in series with each other through a connection groove.

本発明によれば、光線透過率の改善された薄膜光電変換装置用基板を供給でき、高い光電変換効率を有する薄膜光電変換装置を提供できる。   ADVANTAGE OF THE INVENTION According to this invention, the board | substrate for thin film photoelectric conversion apparatuses with improved light transmittance can be supplied, and the thin film photoelectric conversion apparatus which has high photoelectric conversion efficiency can be provided.

本発明に係る薄膜光電変換装置用基板の一例を示す模式的な断面図。The typical sectional view showing an example of the substrate for thin film photoelectric conversion devices concerning the present invention. 集積型薄膜光電変換装置の典型的な一例の素子面を示す模式的な平面図。The typical top view which shows the element surface of a typical example of an integrated thin film photoelectric conversion apparatus. 図２内の楕円２Ａで囲まれた領域における積層構造を拡大して示す模式的な断面図。FIG. 3 is a schematic cross-sectional view showing, in an enlarged manner, a laminated structure in a region surrounded by an ellipse 2A in FIG. 本発明に係る薄膜光電変換装置の一例を、図３中の楕円３Ａで囲まれた領域で拡大して示す模式的な断面図。The typical sectional view expanding and showing an example of the thin film photoelectric conversion device concerning the present invention in the field surrounded by ellipse 3A in FIG. 本発明に係る薄膜光電変換装置用基板の相対反射率を比較した図。The figure which compared the relative reflectance of the board | substrate for thin film photoelectric conversion apparatuses which concerns on this invention.

符号の説明Explanation of symbols

２Ａ 図３に対する領域
３Ａ 図４に対する領域
１０ 薄膜光電変換装置用基板
１００ 透光性絶縁基板
１０１ 中間層
１０２ 透明電極層
１０３ 透明電極層分離溝
１０４ 半導体層分割溝
１０５ 裏面電極層分離溝
１１０ 光電変換ユニット
１１１ 一導電型層
１１２ 真性光電変換層
１１３ 逆導電型層
１２０ 裏面電極層
１２１ 導電性酸化物膜
１２２ 金属層2A Region for FIG. 3 3A Region for FIG. 10 Substrate for thin-film photoelectric conversion device 100 Translucent insulating substrate 101 Intermediate layer 102 Transparent electrode layer 103 Transparent electrode layer separation groove 104 Semiconductor layer division groove 105 Back electrode layer separation groove 110 Photoelectric conversion Unit 111 One conductivity type layer 112 Intrinsic photoelectric conversion layer 113 Reverse conductivity type layer 120 Back electrode layer 121 Conductive oxide film 122 Metal layer

以下、本発明の好ましい実施形態について、図面を参照しながら説明する。図１には、本発明の一実施形態による薄膜光電変換装置用基板が模式的な断面図で示されている。   Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a substrate for a thin film photoelectric conversion device according to an embodiment of the present invention.

この薄膜光電変換装置用基板は透光性絶縁基板１００上に中間層１０１、透明電極層１０２が順に堆積されている。透光性絶縁基板１００は薄膜光電変換装置において光入射側に位置することから、より多くの太陽光を透過させて光電変換ユニットに吸収させるために、できるだけ透明であることが好ましい。同様の意図から、太陽光（ｈν）の光入射面における光反射損失を低減させるように、基板の光入射面に無反射コーティングを行うことによって、薄膜光電変換装置の高効率化が図られ得る。   In this thin film photoelectric conversion device substrate, an intermediate layer 101 and a transparent electrode layer 102 are sequentially deposited on a translucent insulating substrate 100. Since the translucent insulating substrate 100 is located on the light incident side in the thin film photoelectric conversion device, it is preferable that the translucent insulating substrate 100 be as transparent as possible in order to transmit more sunlight and absorb it in the photoelectric conversion unit. From the same intention, the efficiency of the thin film photoelectric conversion device can be improved by applying a non-reflective coating to the light incident surface of the substrate so as to reduce the light reflection loss at the light incident surface of sunlight (hν). .

透光性絶縁基板１００として用いられる汎用のガラス板やフィルムは一般に平滑な表面を有しているため、透光性絶縁基板１００上に透明電極層１０２を直接形成した場合、透明電極層１０２やその上にさらに堆積される半導体層の内部応力によって、透明電極層１０２が透光性絶縁基板１００から剥離する可能性が高くなる。従って、本発明の薄膜光電変換装置用基板１０としては、平滑な表面を有している透光性基板１００上に中間層１０１を形成し、その中間層１０１によって透明電極層１０２が堆積される側に微細な表面凹凸を付与するのが好ましい。   Since a general-purpose glass plate or film used as the light-transmitting insulating substrate 100 generally has a smooth surface, when the transparent electrode layer 102 is directly formed on the light-transmitting insulating substrate 100, the transparent electrode layer 102 or There is a high possibility that the transparent electrode layer 102 is peeled off from the light-transmitting insulating substrate 100 due to the internal stress of the semiconductor layer further deposited thereon. Therefore, as the thin film photoelectric conversion device substrate 10 of the present invention, the intermediate layer 101 is formed on the transparent substrate 100 having a smooth surface, and the transparent electrode layer 102 is deposited by the intermediate layer 101. It is preferable to provide fine surface irregularities on the side.

また、中間層１０１の透明電極層１０２側に形成される微細な凹凸の凸部は曲面からなるのが好ましい。凸部が曲面であることによって、その上に順次堆積される薄膜の結晶成長の際、中間層１０１の形状を起点とする結晶粒界の増加を防止でき、薄膜の電気特性の低下を抑えられるからである。   Moreover, it is preferable that the fine uneven protrusions formed on the transparent electrode layer 102 side of the intermediate layer 101 have a curved surface. Since the convex portion is a curved surface, it is possible to prevent an increase in crystal grain boundaries starting from the shape of the intermediate layer 101 during the crystal growth of the thin film sequentially deposited thereon, and to suppress the deterioration of the electrical characteristics of the thin film. Because.

本発明において形成される中間層１０１は、屈折率の異なる２種類以上の粒子を含む金属酸化物膜からなることが好ましい。なぜなら、屈折率の異なる粒子の混合割合で中間層の見かけ上の屈折率を調整できるからである。中間層に用いられる異なる屈折率を有する粒子は、屈折率が１．８〜２．６の高屈折率粒子と屈折率が１．４〜１．７の低屈折率粒子の組合せであることが好ましい。   The intermediate layer 101 formed in the present invention is preferably made of a metal oxide film containing two or more kinds of particles having different refractive indexes. This is because the apparent refractive index of the intermediate layer can be adjusted by the mixing ratio of particles having different refractive indexes. The particles having different refractive indexes used for the intermediate layer may be a combination of high refractive index particles having a refractive index of 1.8 to 2.6 and low refractive index particles having a refractive index of 1.4 to 1.7. preferable.

高屈折率粒子としては、ＺｎＯ、ＳｎＯ2、ＩＴＯ、酸化インジウム（Ｉｎ2Ｏ3）、酸化チタン（ＴｉＯ2）、酸化アルミニウム（Ａｌ2Ｏ3）、酸化ジルコニウム（ＺｒＯ2）、酸化ニオブ（Ｎｂ2Ｏ5）、酸化タンタル（Ｔａ2Ｏ5）、硫化亜鉛（ＺｎＳ）、酸化セリウム（ＣｅＯ2）等が用いられる。As the high refractive index particles, ZnO, SnO 2 , ITO, indium oxide (In 2 O 3 ), titanium oxide (TiO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), niobium oxide (Nb) 2 O 5 ), tantalum oxide (Ta 2 O 5 ), zinc sulfide (ZnS), cerium oxide (CeO 2 ), or the like is used.

また、低屈折率粒子としては、酸化珪素（ＳｉＯ2）、フッ化マグネシウム（ＭｇＦ2）、フッ化カルシウム（ＣａＦ2）等が用いられる。特に、ＳｉＯ2は可視光領域の透明度が高いため、光入射側に使用する低屈折率材料として好適である。As the low refractive index particles, silicon oxide (SiO 2 ), magnesium fluoride (MgF 2 ), calcium fluoride (CaF 2 ), or the like is used. In particular, since SiO 2 has high transparency in the visible light region, it is suitable as a low refractive index material used on the light incident side.

また、中間層に含まれる高屈折率粒子の粒径は、低屈折率粒子の粒径よりも小さく、低屈折率粒子の粒径の１／４〜３／４であることが好ましく、１／４〜１／２であることがさらに好ましい。この範囲の粒径であれば、屈折率の異なる２種類以上の粒子からなる中間層１０１の見かけ上の屈折率は、透光性絶縁基板１００と透明電極層１０２の間の値とすることができる。その上、この範囲の粒径であれば、相対的に粒径の大きな低屈折率粒子同士の隙間や、低屈折率粒子と透光性絶縁基板の隙間に高屈折率粒子を充填することができるため、好ましい。   Further, the particle size of the high refractive index particles contained in the intermediate layer is preferably smaller than the particle size of the low refractive index particles and is ¼ to ¾ of the particle size of the low refractive index particles. More preferably, it is 4 to 1/2. If the particle size is within this range, the apparent refractive index of the intermediate layer 101 composed of two or more kinds of particles having different refractive indexes may be a value between the translucent insulating substrate 100 and the transparent electrode layer 102. it can. In addition, if the particle size is in this range, the gap between the low refractive index particles having a relatively large particle size, or the gap between the low refractive index particle and the translucent insulating substrate can be filled with the high refractive index particles. This is preferable because it is possible.

さらに、中間層１０１の平均膜厚は５０〜２００ｎｍの範囲であることが好ましい。なぜなら、中間層が薄すぎれば、中間層における屈折率の傾斜が十分に形成できないため中間層の効果が発揮されず、中間層が厚すぎれば、中間層の透明電極層側に形成される表面凹凸が大きすぎて、その上に順次堆積される透明電極層や光電変換ユニットの結晶成長に影響し、光電変換効率を低下させる原因となるからである。   Furthermore, the average film thickness of the intermediate layer 101 is preferably in the range of 50 to 200 nm. This is because if the intermediate layer is too thin, the refractive index gradient in the intermediate layer cannot be sufficiently formed, so that the effect of the intermediate layer is not exhibited. If the intermediate layer is too thick, the surface formed on the transparent electrode layer side of the intermediate layer This is because the unevenness is too large, affecting the crystal growth of the transparent electrode layer and the photoelectric conversion unit sequentially deposited thereon, and causing a decrease in photoelectric conversion efficiency.

微粒子を含む中間層１０１を透光性絶縁基体１００の表面に形成させる方法は特に限定されないが、溶媒を含んだバインダー形成材料と共に塗布する方法が望ましい。微粒子同士、および微粒子と透光性絶縁基体１００の間の付着強度を向上させる役割を果たす接着層は、長期信頼性や光電変換ユニット形成条件（特に温度）に対する耐久性を考慮すると無機材料が好ましい。具体的には、シリコン酸化物、アルミニウム酸化物、チタン酸化物、ジルコニウム酸化物およびタンタル酸化物などの金属酸化物が挙げられる。特に、ガラス基板にＳｉＯ2微粒子を付着させる場合、同じシリコンを主成分とするシリコン酸化物を接着層に使用すると、シリサイド結合の形成により付着力が強固であり、透明性も良く、屈折率も基板や微粒子に近いため、好ましい。The method for forming the intermediate layer 101 containing fine particles on the surface of the light-transmitting insulating substrate 100 is not particularly limited, but a method of coating with a binder forming material containing a solvent is desirable. The adhesive layer that plays a role in improving the adhesion strength between the fine particles and between the fine particles and the translucent insulating substrate 100 is preferably an inorganic material in consideration of long-term reliability and durability against photoelectric conversion unit formation conditions (particularly temperature). . Specific examples include metal oxides such as silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, and tantalum oxide. In particular, when SiO 2 fine particles are adhered to a glass substrate, if silicon oxide mainly composed of the same silicon is used for the adhesive layer, the adhesion is strong due to the formation of silicide bonds, the transparency is good, and the refractive index is also high. It is preferable because it is close to the substrate and fine particles.

透光性絶縁基板１００の表面に上記塗布液を塗布する方法としては、ディッピング法、スピンコート法、バーコート法、スプレー法、ダイコート法、ロールコート法、フローコート法等が挙げられるが、微粒子が緻密な中間層を均一に形成するにはロールコート法が好適に用いられる。塗布操作が完了したら、直ちに塗布薄膜を加熱乾燥する。このようにして形成した膜は、微粒子を含んでいるため、凸部の形状は曲面からなる。   Examples of the method for applying the coating solution on the surface of the light-transmitting insulating substrate 100 include a dipping method, a spin coating method, a bar coating method, a spray method, a die coating method, a roll coating method, and a flow coating method. In order to uniformly form a dense intermediate layer, a roll coat method is preferably used. When the coating operation is completed, the coated thin film is immediately dried by heating. Since the film thus formed contains fine particles, the shape of the convex portion is a curved surface.

また、微粒子が緻密に堆積された中間層では、粒子の大半が透光性絶縁基板１００に接するように形成されるため、粒径の小さな高屈折率粒子は透明電極層１０２よりも透光性絶縁基板１００側に偏って堆積する。そのため、中間層１０１の屈折率は透光性絶縁基板１００側から透明電極層１０２側へ次第に小さくなる傾向を有する。この屈折率の変化が、透光性絶縁基板１００と透明電極層１０２との間で生じる入射光の反射損失を低減させるために好ましい。   In addition, in the intermediate layer in which fine particles are densely deposited, most of the particles are formed so as to be in contact with the light-transmitting insulating substrate 100, so that the high refractive index particles having a small particle diameter are more light-transmitting than the transparent electrode layer 102. The deposition is biased toward the insulating substrate 100 side. Therefore, the refractive index of the intermediate layer 101 tends to gradually decrease from the transparent insulating substrate 100 side to the transparent electrode layer 102 side. This change in refractive index is preferable in order to reduce the reflection loss of incident light generated between the translucent insulating substrate 100 and the transparent electrode layer 102.

透光性絶縁基板１００としてソーダライムガラスを用いた場合は、ガラスからのアルカリ成分が透明電極層１０２やその上に形成される半導体層へ侵入することが懸念される。しかし、本中間層１０１は平均膜厚が５０〜２００ｎｍであり、粒子表面や粒子間には金属酸化物からなるバインダーが存在するため、アルカリバリア膜として機能する。   When soda lime glass is used as the translucent insulating substrate 100, there is a concern that an alkali component from the glass may enter the transparent electrode layer 102 or a semiconductor layer formed thereon. However, the intermediate layer 101 has an average film thickness of 50 to 200 nm and functions as an alkali barrier film because a binder made of a metal oxide is present between the particle surface and between the particles.

加えて、透明電極層１０２を形成した薄膜光電変換装置用基板は、透明薄膜の積層体であるため、光の干渉による色むらが発生しやすくなる傾向があるが、傾斜した屈折率を有する中間層１０１を介在させた場合、干渉による色むらが緩和される作用も有する。   In addition, since the substrate for a thin film photoelectric conversion device on which the transparent electrode layer 102 is formed is a laminate of transparent thin films, color unevenness due to light interference tends to occur, but an intermediate having an inclined refractive index. When the layer 101 is interposed, color unevenness due to interference is also reduced.

透光性絶縁基板上に配置される透明電極層１０２の材料としては、その上に形成される半導体層と接する面に少なくともＺｎＯを含む透明電極層を用いることが好ましい。なぜなら、ＺｎＯは２００℃以下の低温でも光閉じ込め効果を有するテクスチャが形成でき、かつ耐プラズマ性の高い材料であるため、光電変換ユニット１１０が結晶質光電変換層を有する薄膜光電変換装置に好適だからである。例えば、本発明の薄膜光電変換装置用基板のＺｎＯ透明電極層１０２は、基板温度が２００℃以下で減圧条件下のＣＶＤ法にて形成され、粒径が概ね５０〜５００ｎｍで、かつ凹凸の高さが概ね２０〜２００ｎｍの表面凹凸を有する薄膜であることが薄膜光電変換装置の光閉じ込め効果を得る点で好ましい。なお、ここでいう基板温度とは、基板が製膜装置の加熱部と接している面の温度のことをいう。   As a material of the transparent electrode layer 102 disposed on the light-transmitting insulating substrate, it is preferable to use a transparent electrode layer containing at least ZnO on a surface in contact with the semiconductor layer formed thereon. Because ZnO is a material that can form a texture having a light confinement effect even at a low temperature of 200 ° C. or less and has high plasma resistance, the photoelectric conversion unit 110 is suitable for a thin film photoelectric conversion device having a crystalline photoelectric conversion layer. It is. For example, the ZnO transparent electrode layer 102 of the substrate for a thin film photoelectric conversion device of the present invention is formed by a CVD method under a reduced pressure condition at a substrate temperature of 200 ° C. or less, and has a particle size of approximately 50 to 500 nm and a high unevenness. A film having a surface roughness of approximately 20 to 200 nm is preferable from the viewpoint of obtaining the light confinement effect of the thin film photoelectric conversion device. The substrate temperature here means the temperature of the surface where the substrate is in contact with the heating unit of the film forming apparatus.

透明電極層１０２がＺｎＯを主とする薄膜のみで構成されている場合、ＺｎＯ膜の平均厚さは０．７〜５μｍであることが好ましく、１〜３μｍであることがより好ましい。なぜなら、ＺｎＯ膜が薄すぎれば、光閉じ込め効果に有効に寄与する凹凸を十分に付与すること自体が困難となり、また透明電極層として必要な導電性が得にくく、厚すぎればＺｎＯ膜自体による光吸収により、ＺｎＯを透過し光電変換ユニットへ到達する光量が減るため、効率が低下するからである。さらに、厚すぎる場合は、製膜時間の増大によりその製膜コストが増大する。   When the transparent electrode layer 102 is composed only of a thin film mainly composed of ZnO, the average thickness of the ZnO film is preferably 0.7 to 5 μm, and more preferably 1 to 3 μm. This is because if the ZnO film is too thin, it is difficult to sufficiently provide the unevenness that effectively contributes to the light confinement effect, and it is difficult to obtain the necessary conductivity as the transparent electrode layer. This is because the amount of light that passes through ZnO and reaches the photoelectric conversion unit is reduced by absorption, and the efficiency is lowered. Furthermore, when it is too thick, the film forming cost increases due to an increase in the film forming time.

ところで、電力用薄膜光電変換装置のように高電圧で高出力を生じ得る大面積の薄膜光電変換装置を製造する場合、大きな基板上に形成された薄膜光電変換装置を複数個直列接続して用いるのではなく、歩留りを良くするために大きな基板上に形成された薄膜光電変換装置を複数のセルに分割し、それらのセルを直列接続して集積化するのが一般的である。特に、ガラス基板側から光を入射させるタイプの薄膜光電変換装置においては、ガラス基板上に順次半導体層を形成した後、ガラス基板上の透明導電性酸化物（ＴＣＯ）電極の抵抗による損失を低減するために、レーザスクライブ法でその透明電極層を所定幅の短冊状に加工し、その短冊状の長手方向に直行する方向に各セルを直列接続して集積化するのが一般的である。   By the way, when manufacturing a large-area thin film photoelectric conversion device that can generate a high output at a high voltage, such as a power thin film photoelectric conversion device, a plurality of thin film photoelectric conversion devices formed on a large substrate are connected in series. Instead, in order to improve the yield, the thin film photoelectric conversion device formed on a large substrate is generally divided into a plurality of cells, and these cells are connected in series and integrated. In particular, in thin-film photoelectric conversion devices of the type in which light is incident from the glass substrate side, the loss due to resistance of the transparent conductive oxide (TCO) electrode on the glass substrate is reduced after the semiconductor layers are sequentially formed on the glass substrate. For this purpose, the transparent electrode layer is generally processed into a strip having a predetermined width by a laser scribing method, and the cells are generally connected in series in a direction perpendicular to the longitudinal direction of the strip to be integrated.

図２において、集積型薄膜光電変換装置の典型的な一例の素子面が模式的な平面図で示されている。図３は、図２中において楕円２Ａで囲まれた領域の拡大された断面構造を模式的に示している。そして、図４は図３中において楕円３Ａで囲まれた領域のより詳細な積層構造をさらに拡大した模式的な断面図で示している。   In FIG. 2, the element surface of a typical example of the integrated thin film photoelectric conversion device is shown in a schematic plan view. FIG. 3 schematically shows an enlarged cross-sectional structure of a region surrounded by an ellipse 2A in FIG. FIG. 4 is a schematic cross-sectional view further enlarging a more detailed laminated structure of the region surrounded by the ellipse 3A in FIG.

図４において、本発明の一実施形態による集積型薄膜光電変換装置が模式的な断面図で示されている。この薄膜光電変換装置は、透光性絶縁基板１００上に順次堆積された中間層１０１、透明電極層１０２、光電変換ユニット１１０、裏面電極層１２０を含んでいる。そして、光電変換ユニット１１０は、順に堆積されたｐ型又はｎ型の一導電型層１１１、実質的に真性半導体の光電変換層１１２、および逆導電型層１１３を含んでいる。この薄膜光電変換装置に対しては、光電変換されるべき太陽光（ｈν）は透光性絶縁基板１００側から入射される。   FIG. 4 is a schematic cross-sectional view of an integrated thin film photoelectric conversion device according to an embodiment of the present invention. This thin film photoelectric conversion device includes an intermediate layer 101, a transparent electrode layer 102, a photoelectric conversion unit 110, and a back electrode layer 120 that are sequentially deposited on a light-transmitting insulating substrate 100. The photoelectric conversion unit 110 includes a p-type or n-type one conductivity type layer 111, a substantially intrinsic semiconductor photoelectric conversion layer 112, and a reverse conductivity type layer 113, which are sequentially deposited. For this thin film photoelectric conversion device, sunlight (hν) to be subjected to photoelectric conversion is incident from the translucent insulating substrate 100 side.

この透明電極層１０２において、集積化される複数の光電変換セルに対応する複数の領域に分離するために、レーザスクライブによって分離溝１０３が形成される。これらの分離溝１０３は、図３の紙面に直交する方向に直線状に延びている。スクライブ後の残滓は水または有機溶媒を用いた超音波洗浄で除去される。なお、洗浄方法としては、粘着剤や噴射ガスなどを用いて残滓を除去する方法も可能である。   In this transparent electrode layer 102, a separation groove 103 is formed by laser scribing so as to be separated into a plurality of regions corresponding to a plurality of integrated photoelectric conversion cells. These separation grooves 103 extend linearly in a direction perpendicular to the paper surface of FIG. The residue after scribing is removed by ultrasonic cleaning using water or an organic solvent. In addition, as a cleaning method, a method of removing residues using an adhesive or a jet gas is also possible.

分離溝１０３が形成された透明電極層１０２の上には、半導体層からなる光電変換ユニット１１０が形成される。光電変換ユニット１１０には一導電型層１１１、真性光電変換層１１２および逆導電型層１１３が含まれる。光電変換ユニットは図示したように単体としてもよいが、複数のユニットを積層してもよい。光電変換ユニット１１０としては、太陽光の主波長域（４００〜１２００ｎｍ）に吸収を有するものが好ましく、例えば非晶質シリコン系薄膜や結晶質シリコン系薄膜を光電変換層１１２としたユニットが挙げられる。また、「シリコン系」の材料には、シリコンに加え、シリコンカーバイドやシリコンゲルマニウムなど、シリコンを５０％以上含む半導体材料も該当するものとする。   A photoelectric conversion unit 110 made of a semiconductor layer is formed on the transparent electrode layer 102 in which the separation groove 103 is formed. The photoelectric conversion unit 110 includes a one conductivity type layer 111, an intrinsic photoelectric conversion layer 112, and a reverse conductivity type layer 113. The photoelectric conversion unit may be a single unit as illustrated, or a plurality of units may be stacked. As the photoelectric conversion unit 110, one having absorption in the main wavelength range (400 to 1200 nm) of sunlight is preferable. For example, a unit in which an amorphous silicon thin film or a crystalline silicon thin film is used as the photoelectric conversion layer 112 can be given. . In addition to silicon, “silicon-based” materials include semiconductor materials containing 50% or more of silicon, such as silicon carbide and silicon germanium.

非晶質シリコン系薄膜光電変換ユニットや結晶質シリコン系薄膜光電変換ユニットである光電変換ユニット１１０は、例えばｐｉｎ型の順にプラズマＣＶＤ法により各半導体層を積層して形成される。具体的には、例えば導電型決定不純物原子であるボロンが０．０１原子％以上ドープされたｐ型微結晶シリコン系層１１１、光電変換層となる真性非晶質シリコン層や真性結晶質シリコン層１１２、および導電型決定不純物原子であるリンが０．０１原子％以上ドープされたｎ型微結晶シリコン系層１１３をこの順に堆積すればよい。しかし、これら各層は上記に限定されず、例えばｐ型層として非晶質シリコン系膜を用いてもよい。またｐ型層として、非晶質または微結晶のシリコンカーバイド、シリコンゲルマニウムなどの合金材料を用いてもよい。なお、導電型（ｐ型、ｎ型）微結晶シリコン系層の膜厚は３ｎｍ以上１００ｎｍ以下が好ましく、５ｎｍ以上５０ｎｍ以下がさらに好ましい。   The photoelectric conversion unit 110 which is an amorphous silicon-based thin film photoelectric conversion unit or a crystalline silicon-based thin film photoelectric conversion unit is formed by stacking semiconductor layers by a plasma CVD method in the order of, for example, a pin type. Specifically, for example, a p-type microcrystalline silicon-based layer 111 doped with 0.01 atomic% or more of boron, which is a conductivity-determining impurity atom, an intrinsic amorphous silicon layer or an intrinsic crystalline silicon layer serving as a photoelectric conversion layer 112 and an n-type microcrystalline silicon layer 113 doped with 0.01 atomic% or more of phosphorus, which is a conductivity type determining impurity atom, may be deposited in this order. However, these layers are not limited to the above. For example, an amorphous silicon film may be used as the p-type layer. Further, an alloy material such as amorphous or microcrystalline silicon carbide or silicon germanium may be used for the p-type layer. Note that the film thickness of the conductive (p-type, n-type) microcrystalline silicon-based layer is preferably 3 nm to 100 nm, and more preferably 5 nm to 50 nm.

真性光電変換層１１２が真性結晶質シリコン層である場合は、プラズマＣＶＤ法によって基板温度３００℃以下で形成することが好ましい。低温で形成することにより、結晶粒界や粒内における欠陥を終端させて不活性化させる水素原子を多く含ませることが好ましい。具体的には、光電変換層の水素含有量は１〜３０原子％の範囲内にあるのが好ましい。この層は、導電型決定不純物原子の密度が１×１０18ｃｍ-3以下である実質的に真性半導体である薄膜として形成されることが好ましい。さらに、真性結晶質シリコン層１１２に含まれる結晶粒の多くは、透明電極層１０２側から柱状に延びて成長しており、その膜面に対して（１１０）の優先配向面を有することが好ましい。真性結晶質シリコン層１１２の膜厚は十分な光吸収を得るため１μｍ以上が好ましく、結晶質薄膜の内部応力による剥離を抑える観点から１０μｍ以下が好ましい。ただし、薄膜結晶質光電変換ユニット１１０としては、太陽光の主波長域（４００〜１２００ｎｍ）に吸収を有するものが好ましいため、真性結晶質シリコン層に代えて、合金材料である結晶質シリコンカーバイド層（例えば１０原子％以下の炭素を含有する結晶質シリコンからなる結晶質シリコンカーバイド層）や結晶質シリコンゲルマニウム層（例えば３０原子％以下のゲルマニウムを含有する結晶質シリコンからなる結晶質シリコンゲルマニウム層）を形成してもよい。In the case where the intrinsic photoelectric conversion layer 112 is an intrinsic crystalline silicon layer, it is preferably formed at a substrate temperature of 300 ° C. or less by a plasma CVD method. By forming at a low temperature, it is preferable to include many hydrogen atoms that terminate and inactivate defects in the grain boundaries and grains. Specifically, the hydrogen content of the photoelectric conversion layer is preferably in the range of 1 to 30 atomic%. This layer is preferably formed as a thin film that is substantially an intrinsic semiconductor having a conductivity type determining impurity atom density of 1 × 10 18 cm −3 or less. Further, most of the crystal grains contained in the intrinsic crystalline silicon layer 112 are grown in a columnar shape from the transparent electrode layer 102 side, and preferably have a (110) preferential orientation plane with respect to the film surface. . The film thickness of intrinsic crystalline silicon layer 112 is preferably 1 μm or more in order to obtain sufficient light absorption, and is preferably 10 μm or less from the viewpoint of suppressing peeling due to internal stress of the crystalline thin film. However, since the thin film crystalline photoelectric conversion unit 110 preferably has absorption in the main wavelength range (400 to 1200 nm) of sunlight, the crystalline silicon carbide layer, which is an alloy material, is used instead of the intrinsic crystalline silicon layer. (For example, crystalline silicon carbide layer made of crystalline silicon containing 10 atomic% or less of carbon) or crystalline silicon germanium layer (for example, crystalline silicon germanium layer made of crystalline silicon containing 30 atomic% or less of germanium) May be formed.

こうして積層された光電変換ユニット１１０は、透明電極層１０２の場合と同様にレーザスクライブによって形成された半導体層分割溝１０４によって複数の短冊状の半導体領域に分割される。これらの半導体分割溝１０４も図３の紙面に垂直な方向に直線状に延びている。この半導体分割溝１０４は互いに隣接するセル間で透明電極層１０２と裏面電極１２０を電気的に接続するために利用されるものなので、部分的にスクライブの残滓が残っていても問題とならず、超音波洗浄は省略されてもよい。   The stacked photoelectric conversion units 110 are divided into a plurality of strip-shaped semiconductor regions by the semiconductor layer dividing grooves 104 formed by laser scribing as in the case of the transparent electrode layer 102. These semiconductor dividing grooves 104 also extend linearly in a direction perpendicular to the paper surface of FIG. Since the semiconductor dividing groove 104 is used to electrically connect the transparent electrode layer 102 and the back electrode 120 between cells adjacent to each other, even if a scribe residue remains partially, Ultrasonic cleaning may be omitted.

レーザパターニングされた半導体層１１０の上には、裏面電極層１２０が形成される。裏面電極層１２０としては、Ａｌ、Ａｇ、Ａｕ、Ｃｕ、ＰｔおよびＣｒから選ばれる少なくとも一つの材料からなる少なくとも一層の金属層１２２をスパッタ法または蒸着法により形成することが好ましい。また、光電変換ユニット１１０と金属層１２２との間に、ＩＴＯ、ＳｎＯ2、ＺｎＯ等の透明電極層からなる層１２１を形成することが好ましい。この透明導電層１２１は、光電変換ユニット１１０と金属層１２２との間の密着性を高め、金属層１２２の光反射率を高め、光電変換ユニット１１０の化学変化を防止する機能を有する。A back electrode layer 120 is formed on the laser patterned semiconductor layer 110. As the back electrode layer 120, it is preferable to form at least one metal layer 122 made of at least one material selected from Al, Ag, Au, Cu, Pt and Cr by sputtering or vapor deposition. Between the photoelectric conversion unit 110 and the metal layer 122, ITO, it is preferable to form a layer 121 made of a transparent electrode layer of SnO 2, ZnO and the like. The transparent conductive layer 121 has a function of improving the adhesion between the photoelectric conversion unit 110 and the metal layer 122, increasing the light reflectance of the metal layer 122, and preventing the chemical change of the photoelectric conversion unit 110.

裏面電極層１２０は半導体層１１０と同様のレーザスクライブによってパターニングされ、半導体層１１０とともに裏面電極層１２０を局所的に吹き飛ばすことによって複数の裏面電極分離溝１０５が形成された後、超音波洗浄される。これによって複数の短冊状薄膜光電変換装置セルが形成され、それらのセルは接続用溝を介して互いに電気的に直列接続されていることになる。最後に、図示はしていないが、薄膜光電変換装置の裏面側は封止樹脂が付与されて保護される。   The back electrode layer 120 is patterned by laser scribing similar to that of the semiconductor layer 110, and a plurality of back electrode separation grooves 105 are formed by locally blowing the back electrode layer 120 together with the semiconductor layer 110, followed by ultrasonic cleaning. . Thus, a plurality of strip-shaped thin film photoelectric conversion device cells are formed, and these cells are electrically connected in series with each other through the connection grooves. Finally, although not shown, the back surface side of the thin film photoelectric conversion device is protected by a sealing resin.

また、本発明の薄膜光電変換装置の一例として、透明電極層１０２上に非晶質シリコン系光電変換ユニットと結晶質シリコン系光電変換ユニットを順に積層したタンデム薄膜光電変換装置が挙げられる（図示せず）。非晶質シリコン系光電変換ユニットは約３６０〜８００ｎｍの光に感度を有し、結晶質シリコン系光電変換ユニットはそれより長い約１２００ｎｍまでの光を光電変換することが可能であるため、光入射側から非晶質シリコン系光電変換ユニット、結晶質シリコン系光電変換ユニットの順で配置される薄膜光電変換装置は、入射光をより広い範囲で有効利用可能な薄膜光電変換装置となる。従って、このような結晶質光電変換ユニットを含むタンデム薄膜光電変換装置にも、本発明の薄膜光電変換装置用基板は好ましい。   An example of the thin film photoelectric conversion device of the present invention is a tandem thin film photoelectric conversion device in which an amorphous silicon photoelectric conversion unit and a crystalline silicon photoelectric conversion unit are sequentially stacked on a transparent electrode layer 102 (not shown). ) The amorphous silicon photoelectric conversion unit is sensitive to light of about 360 to 800 nm, and the crystalline silicon photoelectric conversion unit can photoelectrically convert light up to about 1200 nm longer than that. The thin film photoelectric conversion device arranged in this order from the amorphous silicon photoelectric conversion unit to the crystalline silicon photoelectric conversion unit is a thin film photoelectric conversion device that can effectively use incident light in a wider range. Therefore, the substrate for a thin film photoelectric conversion device of the present invention is also preferable for a tandem thin film photoelectric conversion device including such a crystalline photoelectric conversion unit.

以下、本発明を実施例に基づいて詳細に説明するが、本発明はその趣旨を超えない限り以下の記載例に限定されるものではない。   EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to the following description examples, unless the meaning is exceeded.

（実施例１）
実施例１として図１に示されるような薄膜光電変換装置用基板を作製した。(Example 1)
As Example 1, a thin film photoelectric conversion device substrate as shown in FIG.

厚み０．７ｍｍ、１２５ｍｍ角のガラス基板１０１上にＳｉＯ2微粒子とＴｉＯ2微粒子を含む中間層１０１を形成した。中間層１０１を形成する際に用いた塗布液は、平均粒径が１００ｎｍの球状シリカ分散液、平均粒径が３０ｎｍの球状酸化チタン分散液（ルチル型）、水、エチルセロソルブの混合液にテトラエトキシシランを加え、更に塩酸を添加したものを用いた。塩酸によってテトラエトキシシランは加水分解され、バインダーのＳｉＯ2となる。球状シリカ（ＳｉＯ2微粒子）と球状酸化チタン（ＴｉＯ2微粒子）は５：２の重量比で混合した。また、球状材料とバインダー（ＳｉＯ2に換算）は、４：１の重量比とした。An intermediate layer 101 containing SiO 2 fine particles and TiO 2 fine particles was formed on a glass substrate 101 having a thickness of 0.7 mm and a 125 mm square. The coating liquid used when forming the intermediate layer 101 is a mixture of a spherical silica dispersion having an average particle diameter of 100 nm, a spherical titanium oxide dispersion having an average particle diameter of 30 nm (rutile type), water, and ethyl cellosolve. Ethoxysilane was added and hydrochloric acid was added. Tetraethoxysilane is hydrolyzed by hydrochloric acid and becomes SiO 2 as a binder. Spherical silica (SiO 2 fine particles) and spherical titanium oxide (TiO 2 fine particles) were mixed at a weight ratio of 5: 2. The spherical material and the binder (converted to SiO 2 ) were in a weight ratio of 4: 1.

塗布液を印刷機にてガラス上に塗布した後、９０℃で３０分乾燥し、その後４００℃で５分加熱することにより、表面に微細な凹凸が形成されたガラス基板を得た。得られた中間層１０１の表面を原子間力顕微鏡（ＡＦＭ）で観察したところ、微粒子の形状を反映した凸部が曲面からなる凹凸が確認された。なお、粒径の大きなＳｉＯ2微粒子同士は厚さ方向に重なることなく、ＳｉＯ2微粒子間やガラスとＳｉＯ2微粒子との隙間に粒径の小さなＴｉＯ2微粒子が充填されていた。After apply | coating a coating liquid on glass with a printing machine, after drying for 30 minutes at 90 degreeC, the glass substrate in which the fine unevenness | corrugation was formed on the surface was obtained by heating for 5 minutes at 400 degreeC after that. When the surface of the obtained intermediate layer 101 was observed with an atomic force microscope (AFM), irregularities in which the convex portions reflecting the shape of the fine particles were curved surfaces were confirmed. Incidentally, the SiO 2 fine particles big particle size without overlapping in the thickness direction, the particle size of the small TiO 2 particles was filled in the gap between the between the SiO 2 particles and glass and SiO 2 particles.

得られた中間層１０１の上にＺｎＯからなる透明電極層１０２を形成した。この透明電極層１０２は、基板温度を１６０℃に設定し、原料ガスとしてジエチルジンク（ＤＥＺ）と水、ドーパントガスとしてジボランガスを供給し、減圧条件下ＣＶＤ法にて形成している。得られたＺｎＯ膜からなる透明電極層１０２の厚さは１．６μｍであり、シート抵抗は９Ω／□程度、ヘイズ率は２３％であった。ヘイズ率とは、ＪＩＳ Ｋ７１３６に記載されているように、（拡散透過率／全光線透過率）×１００で表されるものである。   A transparent electrode layer 102 made of ZnO was formed on the obtained intermediate layer 101. This transparent electrode layer 102 is formed by a CVD method under reduced pressure conditions by setting the substrate temperature to 160 ° C., supplying diethyl zinc (DEZ) and water as source gases, and diborane gas as a dopant gas. The thickness of the transparent electrode layer 102 made of the obtained ZnO film was 1.6 μm, the sheet resistance was about 9Ω / □, and the haze ratio was 23%. The haze ratio is represented by (diffuse transmittance / total light transmittance) × 100 as described in JIS K7136.

また、この基板の相対反射率を、ガラス側から光を入射し、分光光度計にて測定した。この時、測定する基板に対して反射角８°の直接反射光を積分球により測定した。なお、測定時、裏面に位置する透明電極層の凹凸面からの反射光の影響を低減させるために、透明電極層の凹凸面側には屈折率１．７の調整液（ジヨードメタン）を塗布し、カバーガラスで保護した。５５０ｎｍでの相対反射率は８．６％であった。   Further, the relative reflectance of the substrate was measured with a spectrophotometer by entering light from the glass side. At this time, direct reflected light with a reflection angle of 8 ° was measured with an integrating sphere with respect to the substrate to be measured. During measurement, an adjustment liquid (diiodomethane) having a refractive index of 1.7 is applied to the uneven surface side of the transparent electrode layer in order to reduce the influence of reflected light from the uneven surface of the transparent electrode layer located on the back surface. Protected with a cover glass. The relative reflectance at 550 nm was 8.6%.

（比較例１）
比較例１は、実施例１とほぼ同様に厚み０．７ｍｍ、１２５ｍｍ角のガラス基板１０１上に直接ＺｎＯからなる透明電極層１０２を形成した。実施例１と比較すると、中間層１０１が存在しない点が異なる。(Comparative Example 1)
In Comparative Example 1, the transparent electrode layer 102 made of ZnO was directly formed on a glass substrate 101 having a thickness of 0.7 mm and a 125 mm square, almost the same as in Example 1. Compared to Example 1, the difference is that the intermediate layer 101 does not exist.

得られた基板のシート抵抗は９Ω／□程度、ヘイズ率は１９％であった。また、この薄膜光電変換装置用基板の相対反射率は、５５０ｎｍで９．０％であった。   The obtained substrate had a sheet resistance of about 9Ω / □ and a haze ratio of 19%. Moreover, the relative reflectance of this thin film photoelectric conversion device substrate was 9.0% at 550 nm.

図５に実施例１と比較例１で得られた各薄膜光電変換装置用基板の相対反射率スペクトルを示す。この図から、４００〜７００ｎｍの領域において、実施例１の中間層を適用した薄膜光電変換装置用基板は比較例１と比較して低い反射率を示していることが分かる。   FIG. 5 shows the relative reflectance spectrum of each thin film photoelectric conversion device substrate obtained in Example 1 and Comparative Example 1. From this figure, it can be seen that the thin film photoelectric conversion device substrate to which the intermediate layer of Example 1 is applied exhibits a lower reflectance than Comparative Example 1 in the region of 400 to 700 nm.

（実施例２）
実施例２も実施例１と同様に薄膜光電変換装置用基板を作製した。ただし、実施例１と異なるのは、ＳｉＯ2微粒子とＴｉＯ2微粒子を３：１の重量比で混合した点である。この条件で製膜された薄膜光電変換装置用基板のシート抵抗は９Ω／□程度、ヘイズ率は２４％、５５０ｎｍでの相対反射率は、８．３％であった。(Example 2)
In Example 2, a substrate for a thin film photoelectric conversion device was produced in the same manner as in Example 1. However, the difference from Example 1 is that SiO 2 fine particles and TiO 2 fine particles are mixed at a weight ratio of 3: 1. The sheet resistance of the thin film photoelectric conversion device substrate formed under these conditions was about 9Ω / □, the haze ratio was 24%, and the relative reflectance at 550 nm was 8.3%.

（実施例３）
実施例３も実施例１と同様に薄膜光電変換装置用基板を作製した。ただし、実施例１と異なるのは、低屈折率微粒子として平均粒径８０ｎｍのＳｉＯ2微粒子を、また高屈折率微粒子として平均粒径２５ｎｍのＳｎＯ2微粒子を、２：１の重量比で混合した点である。この条件で製膜された薄膜光電変換装置用基板のシート抵抗は９Ω／□程度、ヘイズ率は２３％、５５０ｎｍでの相対反射率は、８．７％であった。(Example 3)
In Example 3, as in Example 1, a thin film photoelectric conversion device substrate was produced. However, the difference from Example 1 is that SiO 2 fine particles having an average particle diameter of 80 nm are mixed as low refractive index fine particles, and SnO 2 fine particles having an average particle diameter of 25 nm are mixed as high refractive index fine particles in a weight ratio of 2: 1. Is a point. The sheet resistance of the thin film photoelectric conversion device substrate formed under these conditions was about 9Ω / □, the haze ratio was 23%, and the relative reflectance at 550 nm was 8.7%.

（実施例４）
実施例４も実施例３と同様に薄膜光電変換装置用基板を作製した。ただし、実施例３と異なるのは、平均粒径８０ｎｍのＳｉＯ2微粒子と平均粒径２５ｎｍのＳｎＯ2微粒子を、５：２の重量比で混合した点である。この条件で製膜された薄膜光電変換装置用基板のシート抵抗は９Ω／□程度、ヘイズ率は２２％、５５０ｎｍでの相対反射率は、８．５％であった。Example 4
In Example 4, as in Example 3, a thin film photoelectric conversion device substrate was produced. However, the difference from Example 3 is that SiO 2 fine particles having an average particle diameter of 80 nm and SnO 2 fine particles having an average particle diameter of 25 nm were mixed at a weight ratio of 5: 2. The sheet resistance of the substrate for a thin film photoelectric conversion device formed under these conditions was about 9Ω / □, the haze ratio was 22%, and the relative reflectance at 550 nm was 8.5%.

表１は上述の実施例１〜４および比較例１における薄膜光電変換装置用基板の主要な特性を示している。   Table 1 shows main characteristics of the thin film photoelectric conversion device substrate in Examples 1 to 4 and Comparative Example 1 described above.

Figure 2006046397
Figure 2006046397

表１の結果から分かるように、実施例１〜４のいずれにおいても、比較例１よりも相対反射率が低い値を示している。また、実施例１〜４の薄膜光電変換装置用基板において、本発明の中間層を挿入した場合、比較例１よりも基板のヘイズ率が高くなっていることが分かる。ヘイズ率は（拡散透過率／全光線透過率）×１００で表されるものであるため、中間層の適用によるヘイズ率値の上昇から薄膜光電変換装置における光閉じ込め効果の向上が期待できる。   As can be seen from the results in Table 1, in each of Examples 1 to 4, the relative reflectance is lower than that in Comparative Example 1. Moreover, in the board | substrate for thin film photoelectric conversion apparatuses of Examples 1-4, when the intermediate | middle layer of this invention is inserted, it turns out that the haze rate of a board | substrate is higher than the comparative example 1. FIG. Since the haze ratio is expressed by (diffuse transmittance / total light transmittance) × 100, an improvement in the light confinement effect in the thin film photoelectric conversion device can be expected from an increase in the haze ratio value due to application of the intermediate layer.

（実施例５〜８、比較例２）
実施例１〜４および比較例１で得られた薄膜光電変換装置用基板を用いて、引き続き集積型薄膜光電変換装置を作製した。透明電極層１０２はレーザスクライブで幅約１００μｍの透明電極層分離溝１０３を形成することによって、約１０ｍｍの幅Ｗおよび１０ｃｍの長さＬを有する短冊状透明電極層に分離される。スクライブ後の残滓は水を用いた超音波洗浄で除去された。(Examples 5 to 8, Comparative Example 2)
Using the thin film photoelectric conversion device substrate obtained in Examples 1 to 4 and Comparative Example 1, an integrated thin film photoelectric conversion device was subsequently produced. The transparent electrode layer 102 is separated into strip-shaped transparent electrode layers having a width W of about 10 mm and a length L of 10 cm by forming a transparent electrode layer separation groove 103 having a width of about 100 μm by laser scribing. Residues after scribing were removed by ultrasonic cleaning using water.

この透明電極層１０２の上に、厚さ１５ｎｍのｐ型非晶質シリコンカーバイド層１１１、厚さ０．３μｍの真性非晶質シリコン光電変換層１１２、及び厚さ２０ｎｍのｎ型微結晶シリコン層１１３からなる非晶質シリコン光電変換ユニット１１０を順次プラズマＣＶＤ法で形成した。   On this transparent electrode layer 102, a p-type amorphous silicon carbide layer 111 having a thickness of 15 nm, an intrinsic amorphous silicon photoelectric conversion layer 112 having a thickness of 0.3 μm, and an n-type microcrystalline silicon layer having a thickness of 20 nm. The amorphous silicon photoelectric conversion unit 110 made of 113 was sequentially formed by the plasma CVD method.

レーザスクライブにて半導体分割溝１０４を形成後、裏面電極１２０として厚さ９０ｎｍのＡｌドープされたＺｎＯ１２１と厚さ２００ｎｍのＡｇ１２２をスパッタ法にて順次形成した。裏面電極分離溝１０５をレーザスクライブした後に超音波洗浄したところ、基板上の膜剥がれ領域は確認されなかった。なお、集積化された後の直列接続されたセルの段数は１０段であった。   After forming the semiconductor dividing groove 104 by laser scribing, 90 nm thick Al-doped ZnO 121 and 200 nm thick Ag 122 were sequentially formed as the back electrode 120 by sputtering. When the back electrode separation groove 105 was subjected to ultrasonic cleaning after laser scribing, no film peeling region on the substrate was confirmed. The number of cells connected in series after integration was ten.

以上のようにして得られた集積型シリコン系薄膜光電変換装置にＡＭ１．５の光を１００ｍＷ／ｃｍ2の光量で照射して出力特性を測定した。それぞれの基板に対して得られた一段あたりの開放電圧（Ｖｏｃ）、短絡電流密度（Ｊｓｃ）、曲線因子（Ｆ．Ｆ．）、そして変換効率の値を表２に示す。The integrated silicon thin film photoelectric conversion device obtained as described above was irradiated with AM1.5 light at a light amount of 100 mW / cm 2 to measure the output characteristics. Table 2 shows the values of open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), and conversion efficiency obtained for each substrate.

Figure 2006046397
Figure 2006046397

表２の結果から分かるように、実施例５〜８のいずれにおいても、比較例２よりも変換効率が向上した。全ての実施例において、Ｊｓｃの値が向上していることから、中間層を挿入したことによる反射低減効果が変換効率の向上に寄与していると考えられる。また、中間層を介在させたことによる薄膜光電変換装置用基板のヘイズ率の向上も、光閉じ込め効果の点からＪｓｃが向上した理由の一つとして挙げられる。   As can be seen from the results in Table 2, in any of Examples 5 to 8, the conversion efficiency was improved as compared with Comparative Example 2. In all the examples, since the value of Jsc is improved, it is considered that the reflection reduction effect due to the insertion of the intermediate layer contributes to the improvement of the conversion efficiency. In addition, an improvement in the haze ratio of the substrate for a thin film photoelectric conversion device due to the interposition of the intermediate layer can be cited as one of the reasons that Jsc is improved in terms of the light confinement effect.

（実施例９）
実施例９においては、実施例１の薄膜光電変換装置用基板を用いて、集積型タンデム薄膜光電変換装置を作製した。実施例５と同様にプラズマＣＶＤ法により、非晶質シリコン光電変換ユニットを形成した後、続いてプラズマＣＶＤ法により厚さ１５ｎｍのｐ型微結晶シリコン層、厚さ１．６μｍの真性結晶質シリコン光電変換層、および厚さ１５ｎｍのｎ型微結晶シリコン層からなる結晶質シリコン光電変換ユニットを形成した。その後、レーザースクライブにより半導体分割溝１０４を形成後、裏面電極１２０として厚さ９０ｎｍのＡｌドープされたＺｎＯ１２１と厚さ２００ｎｍのＡｇ１２２をスパッタ法にて順次形成した。裏面電極分離溝１０５をレーザスクライブした後に超音波洗浄したところ、半導体層部分の膜厚が実施例５〜８に比べて厚くなっているにも関わらず、基板上の膜剥がれ領域は確認されなかった。Example 9
In Example 9, an integrated tandem thin film photoelectric conversion device was fabricated using the thin film photoelectric conversion device substrate of Example 1. After forming an amorphous silicon photoelectric conversion unit by plasma CVD as in Example 5, subsequently, a p-type microcrystalline silicon layer having a thickness of 15 nm and intrinsic crystalline silicon having a thickness of 1.6 μm are formed by plasma CVD. A crystalline silicon photoelectric conversion unit comprising a photoelectric conversion layer and an n-type microcrystalline silicon layer having a thickness of 15 nm was formed. Then, after forming the semiconductor dividing grooves 104 by laser scribing, 90 nm thick Al-doped ZnO 121 and 200 nm thick Ag 122 were sequentially formed as the back electrode 120 by sputtering. When the back surface electrode separation groove 105 was subjected to ultrasonic cleaning after laser scribing, the film peeling region on the substrate was not confirmed even though the film thickness of the semiconductor layer portion was thicker than those in Examples 5 to 8. It was.

得られたシリコン系タンデム型薄膜光電変換装置にＡＭ１．５の光を１００ｍＷ／ｃｍ2の光量で照射して出力特性を測定したところ、一段あたりのＶｏｃが１．３９Ｖ、Ｊｓｃが１３．２ｍＡ／ｃｍ2、Ｆ．Ｆ．が７１．２％、そして変換効率が１３．１％であった。When the output characteristics were measured by irradiating the obtained silicon-based tandem-type thin film photoelectric conversion device with AM 1.5 light at a light quantity of 100 mW / cm 2 , Voc per stage was 1.39 V, and Jsc was 13.2 mA / cm 2 , F.M. F. Of 71.2% and a conversion efficiency of 13.1%.

以上詳細に説明したように、本発明によれば、容易に形成可能であり、透明電極層側の界面において凸部が曲面を有し、かつ屈折率が変化している中間層を有する薄膜光電変換装置用基板を用いて、性能の高い集積型薄膜光電変換装置を提供することができる。   As described above in detail, according to the present invention, a thin film photoelectric device that can be easily formed and has an intermediate layer in which a convex portion has a curved surface and a refractive index changes at the interface on the transparent electrode layer side. An integrated thin film photoelectric conversion device with high performance can be provided by using the conversion device substrate.

Claims (7)

透光性絶縁基板上に、中間層および少なくとも酸化亜鉛を含む透明電極層をこの順に形成した薄膜光電変換装置用基板であって、該中間層内の屈折率が該透光性絶縁基板側から該透明電極層側に向かって滑らかに変化し、かつ該中間層は該透明電極層側の界面に凸部が曲面からなる表面凹凸を有することを特徴とする薄膜光電変換装置用基板。   A thin film photoelectric conversion device substrate in which an intermediate layer and a transparent electrode layer containing at least zinc oxide are formed in this order on a light-transmitting insulating substrate, the refractive index in the intermediate layer from the light-transmitting insulating substrate side A substrate for a thin film photoelectric conversion device, wherein the substrate changes smoothly toward the transparent electrode layer side, and the intermediate layer has surface irregularities having convex surfaces at the interface on the transparent electrode layer side. 請求項１に記載の薄膜光電変換装置用基板であって、前記中間層は屈折率の異なる２種類以上の粒子を含む金属酸化物膜からなることを特徴とする薄膜光電変換装置用基板。   The thin film photoelectric conversion device substrate according to claim 1, wherein the intermediate layer is made of a metal oxide film including two or more kinds of particles having different refractive indexes. 請求項２に記載の薄膜光電変換装置用基板であって、前記中間層は屈折率が１．８〜２．６の高屈折率粒子と屈折率が１．４〜１．７の低屈折率粒子を含むことを特徴とする薄膜光電変換装置用基板。   The thin film photoelectric conversion device substrate according to claim 2, wherein the intermediate layer has a high refractive index particle having a refractive index of 1.8 to 2.6 and a low refractive index of a refractive index of 1.4 to 1.7. A substrate for a thin film photoelectric conversion device comprising particles. 請求項３に記載の薄膜光電変換装置用基板であって、前記中間層に含まれる高屈折率粒子の粒径は低屈折率粒子の粒径よりも小さく、低屈折率粒子の粒径の１／４〜３／４であることを特徴とする薄膜光電変換装置用基板。   4. The thin film photoelectric conversion device substrate according to claim 3, wherein a particle diameter of the high refractive index particles contained in the intermediate layer is smaller than a particle diameter of the low refractive index particles and is 1 of the particle diameter of the low refractive index particles. A substrate for a thin film photoelectric conversion device, characterized in that it is / 4 to 3/4. 請求項１ないし４のいずれかに記載の薄膜光電変換装置用基板であって、前記中間層の平均膜厚は５０〜２００ｎｍの範囲であることを特徴とする薄膜光電変換装置用基板。   5. The thin film photoelectric conversion device substrate according to claim 1, wherein an average film thickness of the intermediate layer is in a range of 50 to 200 nm. 請求項１ないし５のいずれかに記載の薄膜光電変換装置用基板であって、前記透明電極層は０．７μｍ以上の膜厚を有することを特徴とする薄膜光電変換装置用基板。   The thin film photoelectric conversion device substrate according to claim 1, wherein the transparent electrode layer has a thickness of 0.7 μm or more. 請求項１ないし６のいずれかに記載の薄膜光電変換装置用基板を備え、該薄膜光電変換装置用基板の前記透明電極層とその上に堆積された少なくとも一つの光電変換ユニットおよび裏面電極層が複数の光電変換セルを形成するように複数の分離溝によって分離されていて、かつそれらの複数の光電変換セルが接続用溝を介して互いに電気的に直列接続されてなることを特徴とする集積型薄膜光電変換装置。   A thin film photoelectric conversion device substrate according to claim 1, wherein the transparent electrode layer of the thin film photoelectric conversion device substrate and at least one photoelectric conversion unit and a back electrode layer deposited thereon are provided. An integrated circuit characterized in that it is separated by a plurality of separation grooves so as to form a plurality of photoelectric conversion cells, and the plurality of photoelectric conversion cells are electrically connected in series with each other through a connection groove. Type thin film photoelectric conversion device.
JP2006542332A 2004-10-28 2005-10-11 Substrate for thin film photoelectric conversion device and integrated thin film photoelectric conversion device using the same Pending JPWO2006046397A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2004314433 2004-10-28
JP2004314433 2004-10-28
PCT/JP2005/018674 WO2006046397A1 (en) 2004-10-28 2005-10-11 Substrate for thin film photoelectric converter and integrated thin film photoelectric converter employing it

Publications (1)

Publication Number Publication Date
JPWO2006046397A1 true JPWO2006046397A1 (en) 2008-05-22

Family

ID=36227641

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2006542332A Pending JPWO2006046397A1 (en) 2004-10-28 2005-10-11 Substrate for thin film photoelectric conversion device and integrated thin film photoelectric conversion device using the same

Country Status (2)

Country Link
JP (1) JPWO2006046397A1 (en)
WO (1) WO2006046397A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013175506A (en) * 2012-02-23 2013-09-05 Shimane Univ Light scattering film and production method therefor, solar cell

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009206279A (en) * 2008-02-27 2009-09-10 Sharp Corp Thin film solar battery and method for manufacturing the same
DE112009001642B4 (en) * 2008-07-07 2016-09-22 Mitsubishi Electric Corp. Thin-film solar cell and process for its production
KR20110036060A (en) * 2008-08-05 2011-04-06 아사히 가라스 가부시키가이샤 Transparent conductive film substrate and solar cell using the substrate
KR101592576B1 (en) 2009-03-31 2016-02-05 엘지이노텍 주식회사 Solar cell and method of fabricating the same
FR2961952B1 (en) * 2010-06-23 2013-03-29 Commissariat Energie Atomique SUBSTRATE COMPRISING A CONDUCTIVE TRANSPARENT OXIDE LAYER AND METHOD FOR MANUFACTURING THE SAME
JP2012089712A (en) * 2010-10-20 2012-05-10 Mitsubishi Electric Corp Thin film solar cell and method for manufacturing the same
JP5810548B2 (en) * 2011-02-22 2015-11-11 三菱マテリアル株式会社 Transparent substrate with composite film for solar cell and method for producing the same

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2663414B2 (en) * 1988-12-30 1997-10-15 太陽誘電株式会社 Amorphous semiconductor solar cell
JP3416024B2 (en) * 1997-05-23 2003-06-16 シャープ株式会社 Fine particle coating film in thin film solar cell
JPH11135817A (en) * 1997-10-27 1999-05-21 Sharp Corp Photoelectric conversion element and its manufacture
JP2000183376A (en) * 1998-12-17 2000-06-30 Nisshin Steel Co Ltd Insulation base material for solar cell and manufacturing method for the board
JP3247876B2 (en) * 1999-03-09 2002-01-21 日本板硝子株式会社 Glass substrate with transparent conductive film
JP4527272B2 (en) * 1999-12-13 2010-08-18 日本板硝子株式会社 Low reflection glass article
AUPR719801A0 (en) * 2001-08-23 2001-09-13 Pacific Solar Pty Limited Glass beads coating process
JP3706835B2 (en) * 2002-02-19 2005-10-19 株式会社カネカ Thin film photoelectric converter

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013175506A (en) * 2012-02-23 2013-09-05 Shimane Univ Light scattering film and production method therefor, solar cell

Also Published As

Publication number Publication date
WO2006046397A1 (en) 2006-05-04

Similar Documents

Publication Publication Date Title
JP5600660B2 (en) Thin film solar cell substrate and method for manufacturing thin film solar cell
JP4222500B2 (en) Silicon-based thin film photoelectric conversion device
JP2005311292A (en) Substrate for thin film solar cell, manufacturing method therefor, and thin film solar cell using the same
JP5069790B2 (en) Thin film photoelectric conversion device substrate, thin film photoelectric conversion device including the same, and method for manufacturing thin film photoelectric conversion device substrate
US20080223436A1 (en) Back reflector for use in photovoltaic device
US20080105293A1 (en) Front electrode for use in photovoltaic device and method of making same
US20080105298A1 (en) Front electrode for use in photovoltaic device and method of making same
JP3706835B2 (en) Thin film photoelectric converter
JP5243697B2 (en) Transparent conductive film for photoelectric conversion device and manufacturing method thereof
JPWO2006046397A1 (en) Substrate for thin film photoelectric conversion device and integrated thin film photoelectric conversion device using the same
JPWO2008062685A1 (en) Substrate with transparent conductive film for photoelectric conversion device, method for producing the same, and photoelectric conversion device using the same
KR20110070541A (en) Thin film solar cell and method for fabricaitng the same
JP2000252500A (en) Silicon thin-film photoelectric conversion device
US20130104971A1 (en) Transparent conductive structure
JP4713819B2 (en) Substrate for thin film photoelectric conversion device and thin film photoelectric conversion device using the same
JP2011114153A (en) Photoelectric conversion device, and method of manufacturing the same
WO2008063305A2 (en) Front electrode for use in photovoltaic device and method of making same
WO2011136177A1 (en) Thin film solar cell and method for manufacturing same, and base with transparent conductive film and method for producing same
JP5469298B2 (en) Transparent conductive film for photoelectric conversion device and method for producing the same
CN201222505Y (en) Solar battery structure
JP5144949B2 (en) Substrate for thin film photoelectric conversion device and method for manufacturing thin film photoelectric conversion device including the same
JP2012089712A (en) Thin film solar cell and method for manufacturing the same
JP2000012879A (en) Transparent electrode for photoelectric converter elements and photoelectric converter element using the same
JP5542025B2 (en) Photoelectric conversion device
JP2012038956A (en) Thin film solar cell module

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20080929

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20090630

RD03 Notification of appointment of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7423

Effective date: 20090717

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20090818

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20091210