JPH11163376A - Thin-film solar cell - Google Patents
Thin-film solar cellInfo
- Publication number
- JPH11163376A JPH11163376A JP9325801A JP32580197A JPH11163376A JP H11163376 A JPH11163376 A JP H11163376A JP 9325801 A JP9325801 A JP 9325801A JP 32580197 A JP32580197 A JP 32580197A JP H11163376 A JPH11163376 A JP H11163376A
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- JP
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- Prior art keywords
- film
- group
- solar cell
- semiconductor thin
- thin
- Prior art date
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Classifications
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- 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
- Y02E10/541—CuInSe2 material PV cells
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- Photovoltaic Devices (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はエネルギー変換効率
が高く、消費資源の少ない太陽電池に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell having high energy conversion efficiency and consuming less resources.
【０００２】[0002]
【従来の技術】I族、III族とVI族元素からなる化合物半
導体薄膜（カルコパイライト構造半導体薄膜）であるＣ
ｕＩｎＳｅ2（ＣＩＳ）あるいはＧａを固溶したＣｕ(Ｉ
ｎ,Ｇａ)Ｓｅ2（ＣＩＧＳ）は光吸収係数（α＞１０5ｃ
ｍ-1）が大きいことから、約１μｍの膜厚で太陽光を十
分に吸収することが可能である。従って、半導体を構成
する原材料を少なくできるという利点を有しており、大
面積を必要とするエネルギー用太陽電池の光吸収層に適
している。しかし、現状では、ＣＩＳあるいはＣＩＧＳ
太陽電池においてのＣＩＳあるいはＣＩＧＳ膜の膜厚は
約２μｍとなっている。この理由としては、膜厚を厚く
することによりＣＩＧＳ膜の結晶粒を成長させ、結晶粒
界の密度を減少させるためである。結晶粒界は一般に光
励起されたキャリアを捕獲し再結合させる中心となると
考えられる。しかし、ＣＩＧＳ膜に関しては結晶粒界の
機能は明らかではない。2. Description of the Related Art A compound semiconductor thin film (chalcopyrite structure semiconductor thin film) composed of group I, group III and group VI elements is used.
uInSe 2 (CIS) or Cu (I)
n, Ga) Se 2 (CIGS) has a light absorption coefficient (α> 10 5 c)
Since m −1 ) is large, it is possible to sufficiently absorb sunlight with a film thickness of about 1 μm. Therefore, it has the advantage of being able to reduce the amount of raw materials constituting a semiconductor, and is suitable for a light absorption layer of an energy solar cell requiring a large area. However, at present, CIS or CIGS
The thickness of the CIS or CIGS film in the solar cell is about 2 μm. This is because the crystal grains of the CIGS film are grown by increasing the film thickness, and the density of the crystal grain boundaries is reduced. Grain boundaries are generally considered to be centers for capturing and recombining photoexcited carriers. However, regarding the CIGS film, the function of the crystal grain boundary is not clear.
【０００３】[0003]
【発明が解決しようとする課題】太陽電池の光吸収層の
膜厚を薄くすると、原材料を少なくできるだけでなく、
太陽電池製造のために要するプロセス時間を短くでき
る。従って、原材料の消費量の減少とプロセス時間の短
縮による製造に要するエネルギーの減少により太陽電池
の低コスト化を図ることができる。さらに、プロセス時
間の短縮による量産性の向上による低コスト化を図るこ
とができる。以上から、光吸収層の薄膜化は工業的に大
きな利点がある。しかし、ＣＩＧＳ膜の厚さを１μｍ以
下にすると、以下の点が変換効率の低下に寄与してく
る。When the thickness of the light absorbing layer of the solar cell is reduced, not only can the raw materials be reduced,
The process time required for manufacturing a solar cell can be reduced. Therefore, the cost of the solar cell can be reduced by reducing the consumption of raw materials and the energy required for manufacturing by shortening the process time. Furthermore, cost reduction can be achieved by improving mass productivity by shortening the process time. From the above, thinning the light absorption layer has a great industrial advantage. However, when the thickness of the CIGS film is set to 1 μm or less, the following points contribute to a decrease in conversion efficiency.
【０００４】(1) 結晶粒界の密度の増加 (2) 裏面電極での再結合 (3) 光吸収量の低下 この中で、(1)の結晶粒界はその機能が明らかではない
こととＣＩＧＳの結晶粒が柱状であり、キャリアは結晶
粒に沿って移動することから結晶粒界の影響を受けにく
いことを考慮すると、結晶粒界の密度の増加は効率の低
下にあまり影響を与えないと考えられる。薄膜化による
問題は主に(2)裏面電極の再結合と(3)光吸収量の低下で
ある。(2)裏面電極の再結合の問題は以下の通りであ
る。ＣＩＧＳ膜の拡散長はほぼ１.５μｍ以上であるこ
とが報告されている。拡散長が膜厚以上になると裏面電
極での再結合により消滅する光励起キャリアが増加す
る。ＣＩＧＳ膜と窓層で形成されるｐｎ接合による拡散
電位を介して外部に取り出される光励起キャリアが光電
流となるため、裏面電極で再結合した光励起キャリアは
光電流に寄与しない。従って、光電流が減少する。次に
(3)光吸収量の低下では、薄膜化により十分に太陽光が
吸収されなくなるため、光電流が減少する。また、光起
電圧は光電流と逆方向飽和電流の比の対数に比例するた
め、光電流が大幅に減少すると起電圧も低下することに
なる。(1) Increasing the density of the grain boundaries (2) Recombination at the back electrode (3) Decreasing the amount of light absorption Among them, the function of the grain boundaries in (1) is not clear. Taking into account that the crystal grains of CIGS are columnar and carriers are less likely to be affected by the grain boundaries because the carriers move along the crystal grains, an increase in the density of the grain boundaries does not significantly affect the decrease in efficiency. it is conceivable that. The problems caused by thinning are mainly (2) recombination of the back electrode and (3) reduction of the light absorption. (2) The problem of recombination of the back electrode is as follows. It has been reported that the CIGS film has a diffusion length of about 1.5 μm or more. When the diffusion length exceeds the film thickness, the number of photoexcited carriers that disappear by recombination at the back electrode increases. Since the photoexcited carriers extracted outside via the diffusion potential due to the pn junction formed by the CIGS film and the window layer become photocurrent, the photoexcited carriers recombined at the back electrode do not contribute to the photocurrent. Therefore, the photocurrent decreases. next
(3) When the amount of light absorption is reduced, the solar light is not sufficiently absorbed by the thinning, so that the photocurrent is reduced. Also, the photovoltaic voltage is proportional to the logarithm of the ratio of the photocurrent to the reverse saturation current, so that if the photocurrent decreases significantly, the electromotive voltage also decreases.
【０００５】太陽電池の光吸収層となるＣＩＧＳ膜を１
μｍ以下の膜厚に薄膜化して工業的利点を得るには、以
上の２つの問題点を解決する必要がある。A CIGS film serving as a light absorbing layer of a solar cell is
In order to obtain an industrial advantage by reducing the thickness to a thickness of less than μm, it is necessary to solve the above two problems.
【０００６】[0006]
【課題を解決するための手段】前記課題を解決するた
め、本発明は膜厚が１μｍ以下のI族とIII族とVI族元素
からなる半導体薄膜を光吸収層に用いる薄膜太陽電池を
提供している。さらに、本発明では、光吸収層となる半
導体薄膜の薄膜化による変換効率の低下を防ぐ構成を提
供している。In order to solve the above-mentioned problems, the present invention provides a thin-film solar cell using a semiconductor thin film having a film thickness of 1 μm or less and comprising a group I, group III or group VI element as a light absorbing layer. ing. Further, the present invention provides a configuration for preventing a decrease in conversion efficiency due to a reduction in the thickness of a semiconductor thin film serving as a light absorption layer.
【０００７】はじめに、光吸収層となる半導体薄膜の薄
膜化による裏面電極での再結合の増加を防ぐ太陽電池の
構成として以下の発明を提供している。First, the following invention is provided as a configuration of a solar cell which prevents an increase in recombination at a back electrode due to a thinning of a semiconductor thin film serving as a light absorbing layer.
【０００８】第１の発明は、III族元素としてＩｎ及び
Ｇａを用いる光吸収層となるI族とIII族とVI族元素から
なる半導体薄膜において、ＧａのIII族元素に占める割
合が４０％以上である、すなわちＧａ/（Ｉｎ＋Ｇａ）
≧０.４である半導体薄膜を用いる薄膜太陽電池の構成
である。According to a first aspect of the present invention, in a semiconductor thin film comprising a group I, a group III, and a group VI element serving as a light absorption layer using In and Ga as a group III element, the ratio of Ga to the group III element is 40% or more. That is, Ga / (In + Ga)
This is a configuration of a thin film solar cell using a semiconductor thin film satisfying ≧ 0.4.
【０００９】また、VI族元素としてＳｅ及びＳを用いる
光吸収層となるI族とIII族とVI族元素からなる半導体薄
膜において、ＳのVI族元素に占める割合が４０％以上で
ある、すなわちＳ/（Ｓｅ＋Ｓ）≧０.４である半導体薄
膜を用いる薄膜太陽電池の構成も有効である。Further, in a semiconductor thin film made of a group I, group III and group VI element which is a light absorbing layer using Se and S as group VI elements, the ratio of S to the group VI element is 40% or more. A configuration of a thin-film solar cell using a semiconductor thin film satisfying S / (Se + S) ≧ 0.4 is also effective.
【００１０】第２の発明は、III族元素としてＩｎ及び
Ｇａを用いる光吸収層となるI族とIII族とVI族元素から
なる半導体薄膜において、膜の厚さ方向に対しＩｎとＧ
ａの組成比の相対値が変化する分布を有する半導体薄膜
を用いる薄膜太陽電池の構成である。特に、電極膜と光
吸収層となる半導体薄膜と窓層となる半導体薄膜を積層
してなる構成を含む薄膜太陽電池において、III族元素
としてＩｎ及びＧａを用いる光吸収層となるI族とIII族
とVI族元素からなる半導体薄膜の膜の厚さ方向に対し、
III族元素中に占めるＧａの組成比が電極膜側から窓層
側へと減少する分布を有する半導体薄膜を用いる薄膜太
陽電池の構成が好ましい。According to a second aspect of the present invention, there is provided a semiconductor thin film comprising a group I, a group III, and a group VI element serving as a light absorption layer using In and Ga as a group III element.
This is a configuration of a thin-film solar cell using a semiconductor thin film having a distribution in which the relative value of the composition ratio a changes. In particular, in a thin-film solar cell including a configuration in which an electrode film, a semiconductor thin film serving as a light absorbing layer, and a semiconductor thin film serving as a window layer are stacked, the light absorbing layers using In and Ga as Group III elements are used. In the thickness direction of the semiconductor thin film composed of group VI and group VI elements,
A configuration of a thin-film solar cell using a semiconductor thin film having a distribution in which the composition ratio of Ga in the group III element decreases from the electrode film side to the window layer side is preferable.
【００１１】また、VI族元素としてＳｅ及びＳを用いる
光吸収層となるI族とIII族とVI族元素からなる半導体薄
膜において、膜の厚さ方向に対しＳｅとＳの組成比の相
対値が変化する分布を有する半導体薄膜を用いる薄膜太
陽電池の構成も有効であり、特に、電極膜と光吸収層と
なる半導体薄膜と窓層となる半導体薄膜を積層してなる
薄膜太陽電池において、VI族元素としてＳｅ及びＳを用
いる光吸収層となるI族とIII族とVI族元素からなる半導
体薄膜の膜の厚さ方向に対し、VI族元素中に占めるＳの
組成比が電極膜側から窓層側へと増加する分布を有する
半導体薄膜を用いる薄膜太陽電池の構成が好ましい。Also, in a semiconductor thin film comprising a group I, group III and group VI element which is a light absorbing layer using Se and S as group VI elements, the relative value of the composition ratio of Se and S in the thickness direction of the film. The configuration of a thin-film solar cell using a semiconductor thin film having a distribution in which is changed is also effective, particularly, in a thin-film solar cell in which a semiconductor thin film serving as an electrode film, a light absorbing layer, and a semiconductor thin film serving as a window layer are laminated. The composition ratio of S occupying in the group VI element from the electrode film side to the film thickness direction of the semiconductor thin film composed of the group I, group III, and group VI elements that becomes the light absorption layer using Se and S as the group element. The configuration of a thin-film solar cell using a semiconductor thin film having a distribution increasing toward the window layer is preferable.
【００１２】第３の発明は、電極となるＭｏ膜、Ｍｏと
VI族元素の化合物層、光吸収層となる膜厚が１μｍ以下
のI族とIII族とVI族元素からなる半導体薄膜を積層して
なる構成を含む薄膜太陽電池である。また、前記Ｍｏと
VI族元素の化合物層の厚みが１μｍ以下であることが好
ましい。A third aspect of the present invention relates to a Mo film serving as an electrode,
A thin-film solar cell including a structure in which semiconductor thin films made of Group I, Group III, and Group VI elements each having a thickness of 1 μm or less as a compound layer of a Group VI element and a light absorbing layer are stacked. Also, the Mo and
The thickness of the compound layer of the group VI element is preferably 1 μm or less.
【００１３】次に、光吸収層の薄膜化による光吸収量の
低下を防ぐ太陽電池の構成として以下の発明を提供して
いる。Next, the following invention is provided as a configuration of a solar cell for preventing a reduction in the amount of light absorption due to a reduction in the thickness of the light absorption layer.
【００１４】膜厚が１μｍ以下のI族とIII族とVI族元素
からなる半導体薄膜を光吸収層に用いる薄膜太陽電池に
おいて、表面が凹凸形態である基体を用いる薄膜太陽電
池の構成である。This is a thin-film solar cell using a semiconductor thin film having a film thickness of 1 μm or less made of Group I, Group III and Group VI elements as a light absorbing layer, and using a substrate having an uneven surface.
【００１５】また、本薄膜太陽電池の構成における基体
の材質として、ガラスあるいは焼結体あるいは金属体の
いずれかを用いることが好ましい。また、平坦な基体上
に凹凸形態を有する薄膜を堆積してなる基体を用いるこ
とも有効である。さらに、凹凸の山部と谷部の高低差が
０.１μｍ以上で１０μｍ以下である基体を用いること
が好ましい。It is preferable to use glass, a sintered body, or a metal body as the material of the base in the structure of the thin-film solar cell. It is also effective to use a substrate obtained by depositing a thin film having an uneven shape on a flat substrate. Further, it is preferable to use a substrate having a height difference between the peak and the valley of the unevenness of not less than 0.1 μm and not more than 10 μm.
【００１６】本発明の薄膜太陽電池の構成により、低コ
ストで量産性に富んだ工業的に有利な薄膜太陽電池を提
供することができる。さらに、膜厚１μｍ以下のI族とI
II族元素とVI族元素からなる半導体薄膜を光吸収層に用
いても高い変換効率が得られる太陽電池を提供できる。With the configuration of the thin-film solar cell of the present invention, it is possible to provide a low-cost, mass-productive and industrially advantageous thin-film solar cell. Further, the group I having a thickness of 1 μm or less
A solar cell with high conversion efficiency can be provided even when a semiconductor thin film including a group II element and a group VI element is used for a light absorption layer.
【００１７】[0017]
【発明の実施の形態】以下、本発明の実施の形態につい
て図面を参照しながら説明するが、本発明はここで記述
する実施の形態のみに限定されるものではない。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments described here.
【００１８】（実施の形態１）図１は本発明の一実施の
形態を示す薄膜太陽電池の断面模式図を示している。ガ
ラス基板１上に裏面電極となるＭｏ膜２を形成し、その
上にI族とIII族とVI族元素からなる半導体薄膜であるＣ
ｕ(Ｉｎ,Ｇａ)Ｓｅ2（ＣＩＧＳ）膜３を形成している。
このＣＩＧＳ膜の上に窓層となる半導体薄膜ＣｄＳ膜４
とＺｎＯ膜５及び表面電極となる透明導電膜ＩＴＯ膜６
と反射防止膜ＭｇＦ2膜７を順次形成した構成である。
ＣＩＧＳ膜以外の各層の膜厚は、Ｍｏ膜が約１μｍであ
り、ＣｄＳ膜、ＺｎＯ膜、ＩＴＯ膜とＭｇＦ2膜は全て
約０.１μｍである。(Embodiment 1) FIG. 1 is a schematic sectional view of a thin-film solar cell showing an embodiment of the present invention. A Mo film 2 serving as a back electrode is formed on a glass substrate 1, and a semiconductor thin film C comprising a group I, group III and group VI element is formed thereon.
A u (In, Ga) Se 2 (CIGS) film 3 is formed.
A semiconductor thin film CdS film 4 serving as a window layer is formed on the CIGS film.
And a ZnO film 5 and a transparent conductive ITO film 6 serving as a surface electrode
And an antireflection film MgF 2 film 7 are sequentially formed.
The thickness of each layer other than the CIGS film is approximately 1 μm for the Mo film, and approximately 0.1 μm for the CdS film, the ZnO film, the ITO film, and the MgF 2 film.
【００１９】ＣＩＧＳ膜の膜厚が異なる素子をいくつか
作製し、その太陽電池特性を測定した。太陽電池特性
は、ＡＭ１.５で１００ｍＷ/ｃｍ2の疑似太陽光を照射
した時の電流−電圧曲線から評価した。Several devices having different CIGS film thicknesses were manufactured, and their solar cell characteristics were measured. The solar cell characteristics were evaluated from a current-voltage curve when simulated sunlight of 100 mW / cm 2 was applied at AM 1.5.
【００２０】まず、ＧａのIII族元素に対する含有率が
２０％のＣＩＧＳ膜（Ｃｕ(Ｉｎ0.8Ｇａ0.2)Ｓｅ2、Ｇ
ａ/（Ｉｎ＋Ｇａ）＝０.２）の膜厚に対する太陽電池特
性の変化を図２の○印に示す。ここでは、従来のＣＩＧ
Ｓ太陽電池に用いられている膜厚１.８μｍのＣＩＧＳ
膜を用いた太陽電池の特性を基準として、それぞれの特
性を規格化した値で示している。膜厚０.８〜１.８μｍ
の範囲では開放端電圧（Ｖoc）、曲線因子（ＦＦ）はほ
ぼ変わらないことがわかる。これに対し、短絡光電流Ｊ
ｓｃは膜厚の減少に比例して減少していることがわか
る。従って、膜厚０.８〜１.８μｍの範囲の薄膜化によ
る変換効率の減少はほぼ光電流の減少によることがわか
る。しかし、薄膜化による効率の減少率は小さく、膜厚
０.８μｍのＣＩＧＳ膜を用いた太陽電池でもエネルギ
ー用太陽電池に適用できる。さらに薄膜化した膜厚０.
５μｍのＣＩＧＳ膜を用いた太陽電池ではＶoc、Ｊsc、
ＦＦ全ての特性が大幅に減少している。得られる変換効
率は、従来のＣＩＧＳ太陽電池の１／５に低下してい
る。First, a CIGS film (Cu (In 0.8 Ga 0.2 ) Se 2 , G
The change in the solar cell characteristics with respect to the film thickness of a / (In + Ga) = 0.2) is shown by a circle in FIG. Here, the conventional CIG
1.8 μm thick CIGS used for S solar cell
Based on the characteristics of the solar cell using the film, each characteristic is shown as a normalized value. 0.8-1.8 μm thick
It can be seen that the open-circuit voltage (Voc) and the fill factor (FF) hardly change in the range of. In contrast, the short-circuit photocurrent J
It can be seen that sc decreases in proportion to the decrease in the film thickness. Therefore, it can be understood that the decrease in the conversion efficiency due to the thinning in the thickness range of 0.8 to 1.8 μm is almost due to the decrease in the photocurrent. However, the rate of decrease in efficiency due to thinning is small, and a solar cell using a 0.8 μm-thick CIGS film can be applied to a solar cell for energy. Further reduced film thickness
For a solar cell using a 5 μm CIGS film, Voc, Jsc,
The characteristics of all FFs are greatly reduced. The conversion efficiency obtained is reduced to one fifth of the conventional CIGS solar cell.
【００２１】次に、各膜厚のＣＩＧＳ太陽電池の量子効
率を図３に示す。ＣＩＧＳの膜厚１.２μｍと膜厚１.８
μｍの太陽電池の量子効率がほぼ一致しているため、こ
こでは、膜厚１.８μｍの素子の量子効率のみ示してい
る。膜厚０.８μｍと１.８μｍの太陽電池の量子効率を
比較すると、ＣＩＧＳ膜を薄膜化することにより波長
０.８μｍ以上の長波長感度が大きく低下していること
がわかる。これは以下の理由による。長波長光は入射面
となるＣｄＳ膜とＣＩＧＳ膜の界面から深い部分のＣＩ
ＧＳ膜内部まで透過する。従って、Ｍｏ膜近傍で励起さ
れるキャリアが多くなる。Ｍｏ膜での裏面再結合速度が
速いと多くの光励起キャリアが再結合により消滅するた
め、長波長光感度が劣ることになる。この場合、ＣＩＧ
Ｓ膜の膜厚が拡散長より薄くなると、裏面再結合の影響
が大きくなる。次に、膜厚０.５μｍのＣＩＧＳ膜を用
いた太陽電池では、全波長域で量子効率が大幅に低下し
ている。これは、光を十分に吸収するために必要となる
膜厚より薄くなり、光吸収量が減少したためと考えられ
る。従って、図２のＪscの大幅な低下は光吸収量の減少
によると考えられる。また、Ｖocの低下も光吸収量の減
少と関連することを以下に示す。Next, FIG. 3 shows the quantum efficiency of the CIGS solar cell of each film thickness. CIGS film thickness of 1.2 μm and film thickness of 1.8
Since the quantum efficiencies of μm solar cells are almost the same, only the quantum efficiency of a 1.8 μm-thick element is shown here. Comparing the quantum efficiencies of the 0.8 μm-thick and 1.8 μm-thick solar cells, it can be seen that the long wavelength sensitivity of 0.8 μm or more is greatly reduced by thinning the CIGS film. This is for the following reason. The long-wavelength light has a CI at a deep portion from the interface between the CdS film and the CIGS film serving as an incident surface.
It penetrates into the GS film. Therefore, the number of carriers excited near the Mo film increases. When the back surface recombination speed in the Mo film is high, many photoexcited carriers disappear due to recombination, so that the long-wavelength light sensitivity is deteriorated. In this case, CIG
When the thickness of the S film is smaller than the diffusion length, the influence of the back surface recombination increases. Next, in a solar cell using a CIGS film having a thickness of 0.5 μm, the quantum efficiency is significantly reduced in all wavelength regions. This is presumably because the film thickness became thinner than necessary to sufficiently absorb light, and the amount of light absorption was reduced. Therefore, it is considered that the large decrease in Jsc in FIG. 2 is due to the decrease in the amount of light absorption. It is shown below that the decrease in Voc is also related to the decrease in light absorption.
【００２２】開放端電圧Ｖｏｃは近似的に、 Ｖｏｃ＝ｋＴ／ｑ・ｌｎ（Ｊsc／Ｊ0） （１） で与えられる。ここで、ｋはボルツマン定数、Ｔは絶対
温度、ｑは電荷、Ｊ0は逆方向飽和電流である。式
（１）から、Ｊscが大幅に減少すると、Ｖocも減少する
ことがわかる。従って、膜厚０.５μｍまで薄膜化した
場合の全ての太陽電池特性の大幅な低下は、光吸収量の
減少によると考えられる。The open-circuit voltage Voc is approximately given by: Voc = kT / q · ln (Jsc / J0) (1) Here, k is Boltzmann's constant, T is absolute temperature, q is electric charge, and J0 is reverse saturation current. From equation (1), it can be seen that when Jsc is greatly reduced, Voc is also reduced. Therefore, it is considered that a significant decrease in all solar cell characteristics when the film thickness is reduced to 0.5 μm is due to a decrease in light absorption.
【００２３】以上の結果から、ＧａのIII族元素に対す
る含有率が２０％程度の場合は、ＣＩＧＳ膜の膜厚が
０.８μｍ程度まで薄膜化してもエネルギー用太陽電池
に適用できる十分な変換効率が得られることがわかる。
また、ＧａのIII族元素に占める含有率３０％程度まで
は同様な結果を示した。From the above results, when the content of Ga with respect to the group III element is about 20%, even if the thickness of the CIGS film is reduced to about 0.8 μm, sufficient conversion efficiency applicable to the solar cell for energy is obtained. Is obtained.
Similar results were obtained up to a content of about 30% of Ga in the group III element.
【００２４】次に、ＧａのIII族元素に占める含有率が
６０％（Ｇａ/（Ｉｎ＋Ｇａ）＝０.６）のＣＩＧＳ膜
（Ｃｕ(Ｉｎ0.4Ｇａ0.6)Ｓｅ2）を用いた太陽電池の膜
厚に対する太陽電池特性の変化を図２の黒の三角形で示
す。膜厚０.８〜１.８μｍの範囲で、Ｖoc、Ｊsc、ＦＦ
ともにほぼ変わらないことがわかる。従って、ＣＩＧＳ
膜の膜厚を０.８μｍまで薄膜化しても、従来の膜厚を
用いたＣＩＧＳ太陽電池と変わらない変換効率が得られ
ることがわかる。前記実施例に比較すると、Ｇａ含有率
が高いＣＩＧＳ太陽電池では、膜厚を０.８μｍまで薄
膜化してもＪscが減少しない。これは、Ｇａの含有率が
４０％以上のＣＩＧＳ膜では拡散長が短く、裏面再結合
の影響をほとんど受けないためと考えられる。膜厚０.
５μｍまで薄膜化するとＣｕ(Ｉｎ0.4Ｇａ0.6)Ｓｅ2膜
を用いた太陽電池の場合も、全ての太陽電池特性が大幅
に低下する。これは、光吸収量の減少によるためであ
り、Ｇａの含有率による拡散長の違いに依らない。Next, a solar cell film using a CIGS film (Cu (In 0.4 Ga 0.6 ) Se 2 ) in which the content of Ga in the group III element is 60% (Ga / (In + Ga) = 0.6). The change of the solar cell characteristic with respect to the thickness is shown by a black triangle in FIG. Voc, Jsc, FF in the thickness range of 0.8 to 1.8 μm
It turns out that both are almost the same. Therefore, CIGS
It can be seen that even when the thickness of the film is reduced to 0.8 μm, conversion efficiency that is the same as that of a CIGS solar cell using a conventional film thickness can be obtained. Compared with the above example, in a CIGS solar cell having a high Ga content, Jsc does not decrease even if the film thickness is reduced to 0.8 μm. This is considered to be because the CIGS film having a Ga content of 40% or more has a short diffusion length and is hardly affected by back surface recombination. Thickness 0.
When the thickness is reduced to 5 μm, all solar cell characteristics are significantly reduced even in the case of a solar cell using a Cu (In 0.4 Ga 0.6 ) Se 2 film. This is due to a decrease in light absorption, and does not depend on a difference in diffusion length depending on the Ga content.
【００２５】本実施の形態から、ＣＩＧＳ膜の膜厚を１
μｍ以下の約０.８μｍに薄膜化しても、エネルギー用
太陽電池として有効な変換効率が得られることがわか
る。さらに、ＧａのIII族元素に占める含有率が４０％
以上のＣＩＧＳ膜では、薄膜化に対してより有効である
ことがわかる。According to this embodiment, the thickness of the CIGS film is set to 1
It can be seen that even when the thickness is reduced to about 0.8 μm or less, effective conversion efficiency as an energy solar cell can be obtained. Further, the content of Ga in the group III element is 40%.
It can be seen that the above CIGS film is more effective for thinning.
【００２６】なお、ここでは、ＣＩＧＳ膜のＧａのIII
族元素に占める含有率に対する薄膜化による変換効率の
有効性について述べたが、VI族元素に占めるＳの含有率
に対しても同様な有効性が得られる。つまり、ＳのVI族
元素に占める含有率が４０％以上のＣｕＩｎ(Ｓｅ,Ｓ)2
膜においても拡散長は、ＳのVI族元素に占める含有率が
４０％以下のＣｕＩｎ(Ｓｅ,Ｓ)2膜のそれより短い。従
って、薄膜化による裏面再結合の影響を受けにくい。ま
た、５元化合物Ｃｕ(Ｉｎ,Ｇａ)(Ｓｅ,Ｓ)2の場合も、
ＧａのIII族元素に占める含有率が４０％以上かＳのVI
族元素に占める含有率が４０％以上のどちらかの条件を
満足した膜においては同様な有効性が得られる。Here, the III of Ga of the CIGS film is used.
Although the effectiveness of the conversion efficiency by the thinning with respect to the content in the group VI element has been described, the same effectiveness can be obtained for the content of S in the group VI element. That is, CuIn (Se, S) 2 in which the content of S in the group VI element is 40% or more.
Also in the film, the diffusion length is shorter than that of the CuIn (Se, S) 2 film in which the content of S in the group VI element is 40% or less. Therefore, it is less susceptible to back surface recombination due to thinning. In the case of the quinary compound Cu (In, Ga) (Se, S) 2 ,
The content of Ga in the group III element is 40% or more or the content of S VI
The same effectiveness can be obtained in a film satisfying any one of the conditions in which the content in the group element is 40% or more.
【００２７】（実施の形態２）図１の薄膜太陽電池の構
成において、ＩｎとＧａの膜の深さ方向の組成比が変化
しているＣＩＧＳ膜を用いた太陽電池の特性について述
べる。ここでは、ＣＩＧＳ膜が異なる２種類の太陽電池
を評価している。ＣＩＧＳ膜以外の各膜の構成及び膜厚
は実施の形態１と同様である。(Embodiment 2) Characteristics of a solar cell using a CIGS film in which the composition ratio of the In and Ga films in the depth direction is changed in the configuration of the thin film solar cell of FIG. Here, two types of solar cells having different CIGS films are evaluated. The configuration and thickness of each film other than the CIGS film are the same as in the first embodiment.
【００２８】第１の構成は、Ｍｏ膜上にＩｎを含まない
ＣｕＧａＳｅ2層を形成し、その上にＣｕ(Ｉｎ0.8Ｇａ
0.2)Ｓｅ2層を形成したＣＩＧＳ膜を用いた太陽電池で
ある。In the first configuration, a CuGaSe 2 layer containing no In is formed on a Mo film, and Cu (In 0.8 Ga
0.2 ) A solar cell using a CIGS film having a Se 2 layer formed thereon.
【００２９】ここで用いたＣＩＧＳ膜の膜厚は、ＣｕＧ
ａＳｅ2層が０.１μｍであり、Ｃｕ(Ｉｎ0.8Ｇａ0.2)Ｓ
ｅ2層が０.７μｍである。The thickness of the CIGS film used here is CuG
aSe 2 layer is 0.1 μm and Cu (In 0.8 Ga 0.2 ) S
e 2 layer is 0.7 μm.
【００３０】第２の構成は、ＧａのIII族元素に占める
含有率が膜の深さ方向で徐々に変化しているＣＩＧＳ膜
を用いた太陽電池である。具体的には、ＣｄＳ膜との界
面近傍のＧａの含有率が２０％であり、膜の深さ方向に
徐々にＧａの含有率が増加し、Ｍｏ膜近傍ではＧａの含
有率が６０％となっているＣＩＧＳ膜を用いた。ＣＩＧ
Ｓ膜の膜厚は約０.８μｍである。The second configuration is a solar cell using a CIGS film in which the content of Ga in the group III element gradually changes in the depth direction of the film. Specifically, the Ga content near the interface with the CdS film is 20%, the Ga content gradually increases in the depth direction of the film, and the Ga content near the Mo film is 60%. Used CIGS film. CIG
The thickness of the S film is about 0.8 μm.
【００３１】図４に各々の太陽電池の特性を示す。ここ
では、比較のため実施の形態１で示した膜厚０.８μｍ
のＣｕ(Ｉｎ0.8Ｇａ0.2)Ｓｅ2膜を用いた太陽電池の特
性も示しあり、この太陽電池の特性を基準として、他の
２つの太陽電池の特性を規格化してある。ＣｕＧａＳｅ
２層を設けた第１の構成の太陽電池とＧａの含有率が徐
々に変化している第２の構成の太陽電池ともに前記実施
例の太陽電池より全ての特性が向上していることがわか
る。従って、ＩｎとＧａの膜の深さ方向の組成比が変化
しているＣＩＧＳ膜は、薄膜化に対して有効である。FIG. 4 shows the characteristics of each solar cell. Here, the film thickness of 0.8 μm shown in the first embodiment for comparison.
The characteristics of a solar cell using a Cu (In 0.8 Ga 0.2 ) Se 2 film are also shown. Based on the characteristics of this solar cell, the characteristics of the other two solar cells are standardized. CuGaSe
It can be seen that all the characteristics of the solar cell having the first configuration having two layers and the solar cell having the second configuration in which the content of Ga is gradually changed are higher than those of the solar cell of the above embodiment. . Therefore, a CIGS film in which the composition ratio of the In and Ga films in the depth direction changes is effective for thinning.
【００３２】ここで、ＣｕＩｎＳｅ2とＣｕＧａＳｅ2を
比較すると、ＣｕＧａＳｅ2膜の方が禁制帯幅が広く、
伝導帯が真空準位に近い。混晶体であるＣｕ(Ｉｎ,Ｇ
ａ)Ｓｅ2膜では、Ｇａ濃度が高いほど禁制帯幅が広く、
伝導帯が真空準位に近い。従って、Ｍｏ膜付近のＣｕＧ
ａＳｅ2層を形成すると、伝導帯に不連続が生じ、エネ
ルギー障壁が形成される。光励起されたキャリア（ここ
では電子）のうちＭｏ側に移動するものは障壁で反射さ
れるため、ｐｎ接合（ＣｄＳとＣＩＧＳ膜の界面付近）
側へと移動する。つまり、Ｍｏ膜での裏面再結合を抑制
することができる。また、Ｇａ含有率が徐々にＭｏ膜側
に増加する分布を有するＣＩＧＳ膜では、伝導帯のレベ
ルが徐々に高くなる。この場合、内部電界が生じる。キ
ャリアは内部電界によりｐｎ接合側へと移動することに
なり、Ｍｏ膜での裏面再結合が抑制される。以上からＣ
ＩＧＳ膜内でＩｎとＧａの膜の深さ方向の組成比を変化
させることにより、エネルギー障壁や内部電界を生じさ
せ、裏面でのキャリア再結合を抑制することが可能であ
る。Here, comparing CuInSe 2 and CuGaSe 2 , the CuGaSe 2 film has a wider forbidden band,
The conduction band is close to the vacuum level. Cu (In, G)
a) In the Se 2 film, the higher the Ga concentration, the wider the forbidden band width,
The conduction band is close to the vacuum level. Therefore, CuG near the Mo film
When the aSe 2 layer is formed, a discontinuity occurs in the conduction band, and an energy barrier is formed. Of the photoexcited carriers (electrons in this case) that move to the Mo side are reflected by the barrier, so that the pn junction (near the interface between the CdS and the CIGS film)
Move to the side. That is, the back surface recombination in the Mo film can be suppressed. In a CIGS film having a distribution in which the Ga content gradually increases toward the Mo film, the level of the conduction band gradually increases. In this case, an internal electric field is generated. The carriers move to the pn junction side due to the internal electric field, and the back surface recombination in the Mo film is suppressed. From above, C
By changing the composition ratio of the In and Ga films in the depth direction in the IGS film, an energy barrier and an internal electric field can be generated, and carrier recombination on the back surface can be suppressed.
【００３３】なお、ここでは、III族元素であるＩｎと
Ｇａの膜の深さ方向の組成比が変化しているＣＩＧＳ膜
に対する薄膜化による変換効率の有効性について述べた
が、VI族元素であるＳｅとＳの膜の深さ方向の組成比は
変化しているＣｕＩｎ(Ｓｅ,Ｓ)2膜でも同様な有効性が
得られる。ＣｕＩｎＳ2とＣｕＩｎＳｅ2を比較した場
合、ＣｕＩｎＳ2膜の方が禁制帯幅が広い。また、伝導
帯のエネルギーはＣｕＩｎＳ２の方がＣｕＩｎＳｅ２よ
りわずかに大きい。従って、裏面電極付近のＳ含有率を
高くすると電子に対するエネルギー障壁が形成できる。
また、Ｓ含有率を裏面電極に近づくにつれ高くなるよう
な分布を与えると内部電界が生じる。従って、ＳとＳｅ
の膜の深さ方向の組成比が変化した分布のＣｕＩｎ(Ｓ
ｅ,Ｓ)2膜でも裏面電極の再結合を防止でき、薄膜化し
ても変換効率の低下を抑制できる。さらに、５元化合物
Ｃｕ(Ｉｎ,Ｇａ)(Ｓｅ,Ｓ)2の場合も、III族元素である
ＧａとＩｎの組成比が変化した分布あるいはVI族元素で
あるＳとＳｅの組成比が変化した分布のどちらかを与え
ることにより同様な有効性が得られる。Here, the effectiveness of the conversion efficiency by thinning the CIGS film in which the composition ratio in the depth direction of the film of In and Ga, which is a group III element, is changed has been described. Similar effectiveness can be obtained even with a CuIn (Se, S) 2 film in which the composition ratio of certain Se and S films in the depth direction is changed. If you compare the CuInS2 and CuInSe 2, the forbidden band width towards the CuInS 2 film is wide. Further, the energy of the conduction band is slightly larger in CuInS2 than in CuInSe2. Therefore, when the S content near the back electrode is increased, an energy barrier for electrons can be formed.
Further, when a distribution is made such that the S content increases as approaching the back surface electrode, an internal electric field is generated. Therefore, S and Se
CuIn (S) having a distribution in which the composition ratio in the depth direction of the
The recombination of the back electrode can be prevented even with the e, S) 2 film, and a decrease in the conversion efficiency can be suppressed even when the film is made thin. Further, also in the case of the quinary compound Cu (In, Ga) (Se, S) 2 , the distribution in which the composition ratio of Ga and In which is a group III element is changed or the composition ratio of S and Se which is a group VI element is changed. Similar effectiveness can be obtained by giving either of the distributions given.
【００３４】（実施の形態３）図５は本発明の一実施の
形態を示す薄膜太陽電池の断面模式図を示している。ガ
ラス基板８上に裏面電極となるＭｏ膜９を形成し、その
上かあるいは表面にＭｏとVI族元素の化合物であるＭｏ
Ｓｅ2層１０を形成する。このＭｏＳｅ2層の上にI族とI
II族とVI族元素からなる半導体薄膜であるＣｕ(Ｉｎ,Ｇ
ａ)Ｓｅ2（ＣＩＧＳ）膜１１を形成している。このＣＩ
ＧＳ膜の上に窓層となる半導体薄膜ＣｄＳ膜１２とＺｎ
Ｏ膜１３及び表面電極となる透明導電膜ＩＴＯ膜１４と
反射防止膜ＭｇＦ2膜１５を順次形成した構成である。
ここでは、ＣＩＧＳ膜としてＣｕ(Ｉｎ0.8Ｇａ0.2)Ｓｅ
2を用い、その膜厚は０.８μｍである。ＭｏＳｅ2以外
の他の各層の膜厚は、Ｍｏ膜が約１μｍであり、ＣｄＳ
膜、ＺｎＯ膜、ＩＴＯ膜とＭｇＦ2膜は全て約０.１μｍ
である。(Embodiment 3) FIG. 5 is a schematic sectional view of a thin-film solar cell showing an embodiment of the present invention. A Mo film 9 serving as a back electrode is formed on a glass substrate 8, and Mo or a compound of a group VI element Mo is formed on or on the Mo film 9.
The Se 2 layer 10 is formed. On this MoSe 2 layer, I and I
Cu (In, G) is a semiconductor thin film composed of Group II and Group VI elements.
a) The Se 2 (CIGS) film 11 is formed. This CI
On the GS film, a semiconductor thin film CdS film 12 serving as a window layer and Zn
In this configuration, an O film 13, a transparent conductive film ITO film 14 serving as a surface electrode, and an antireflection film MgF 2 film 15 are sequentially formed.
Here, Cu (In 0.8 Ga 0.2 ) Se is used as the CIGS film.
2 , and the film thickness is 0.8 μm. The thickness of each layer other than MoSe 2 is about 1 μm for the Mo film, and CdS
The film, ZnO film, ITO film and MgF 2 film are all about 0.1 μm
It is.
【００３５】図６にＭｏＳｅ2の厚みが異なる太陽電池
の特性を示す。ＭｏＳｅ２層がない太陽電池（ＭｏＳｅ
2の膜厚０）の特性を基準として、各太陽電池の特性を
規格化してある。ＭｏＳｅ2層が存在することによりＪs
cが向上することがわかる。また、ＭｏＳｅ2膜の膜厚が
０.５μｍとなると曲線因子が少し低下している。FIG. 6 shows the characteristics of solar cells having different MoSe 2 thicknesses. Solar cell without MoSe2 layer (MoSe
The characteristics of each solar cell are standardized based on the characteristics of the film thickness 0) of No. 2 . The presence of the MoSe 2 layer allows Js
It can be seen that c is improved. When the thickness of the MoSe 2 film is 0.5 μm, the fill factor is slightly reduced.
【００３６】ＭｏＳｅ2は半導体であり、ｐ形低抵抗膜
（ｐ+膜）を形成できる。ＣＩＧＳ膜がｐ形半導体であ
ることから、裏面電極Ｍｏ膜上にｐ+ｐ層が形成されて
いることになる。ｐ+ｐ層間にはフェルミ準位の差によ
る電界が生じるため、この電界による障壁によってｐ形
ＣＩＧＳ膜内で生成されたキャリアのうち裏面（Ｍｏ）
に向かうものが反射され、裏面電極部分で再結合しなく
なり、ｐｎ接合部（ＣｄＳ／ＣＩＧＳ界面近傍）に到達
するキャリアが増加する。従って、Ｊscが向上すること
になる。また、ＭｏＳｅ2層の膜厚が増加すると太陽電
池の直列抵抗成分が増大するためＦＦが減少することに
なる。図６からはＭｏＳｅ2層の膜厚０.５μｍからＦＦ
の低下が観測されているが、その低下率は少なく、変換
効率はＭｏＳｅ2層がない場合よりも大きい。ＭｏＳｅ2
層が１μｍまではＦＦの低下よりもＭｏＳｅ２層の存在
によるＪscの向上の影響の方が優っている。従って、Ｍ
ｏＳｅ2膜の膜厚は１μｍ以下が適当である。MoSe 2 is a semiconductor and can form a p-type low resistance film (p + film). Since the CIGS film is a p-type semiconductor, a p + p layer is formed on the back electrode Mo film. Since an electric field is generated between the p + p layers due to the difference in Fermi level, the back surface (Mo) of the carriers generated in the p-type CIGS film by the barrier due to the electric field is generated.
Are reflected, are not recombined at the back electrode portion, and the number of carriers reaching the pn junction (near the CdS / CIGS interface) increases. Therefore, Jsc is improved. Further, when the thickness of the MoSe 2 layer increases, the series resistance component of the solar cell increases, so that the FF decreases. FIG. 6 shows that the MoSe 2 layer has a thickness of 0.5 μm
Is observed, but the rate of decrease is small, and the conversion efficiency is larger than that without the MoSe 2 layer. MoSe 2
Up to a layer thickness of 1 μm, the effect of the improvement of Jsc due to the presence of the MoSe2 layer is superior to the decrease of the FF. Therefore, M
The thickness of the oSe 2 film is suitably 1 μm or less.
【００３７】以上から、ＭｏＳｅ2層とＣＩＧＳ膜で形
成される内部電界は、ＣＩＧＳ膜を薄膜化した場合に問
題となる裏面の再結合を防止するためには有効であるこ
とがわかる。From the above, it can be seen that the internal electric field formed by the MoSe 2 layer and the CIGS film is effective in preventing the back surface recombination which becomes a problem when the CIGS film is thinned.
【００３８】また、ＭｏＳｅ2の他にＭｏ(Ｓｅ,Ｓ)2や
Ｍｏ(Ｓｅ,Ｏ)2等のＭｏとVI族元素の化合物層を裏面電
極とＣＩＧＳ膜の間に挿入した構成の太陽電池でも同様
な結果が得られ、ＣＩＧＳ膜の薄膜化による効率低下を
防ぐのに有効である。A solar cell having a structure in which a compound layer of Mo and a Group VI element such as Mo (Se, S) 2 or Mo (Se, O) 2 is inserted between the back electrode and the CIGS film in addition to MoSe 2. However, a similar result is obtained, which is effective for preventing a decrease in efficiency due to thinning of the CIGS film.
【００３９】（実施の形態４）図７は本発明の一実施の
形態を示す薄膜太陽電池の断面模式図を示している。表
面に微少な凹凸を有するガラス基板１６上に裏面電極と
なるＭｏ膜１７を形成し、その上にI族とIII族とVI族元
素からなる半導体薄膜であるＣｕ(Ｉｎ,Ｇａ)Ｓｅ2（Ｃ
ＩＧＳ）膜１８を形成している。このＣＩＧＳ膜の上に
窓層となる半導体薄膜ＣｄＳ膜１９とＺｎＯ膜２０及び
表面電極となる透明導電膜ＩＴＯ膜２１を順次形成した
構成である。ここでは、ＣＩＧＳ膜としてＣｕ(Ｉｎ0.8
Ｇａ0. 2)Ｓｅ2を用い、その膜厚は０.５μｍである。他
の各層の膜厚は、実施の形態１と同じである。(Embodiment 4) FIG. 7 is a schematic sectional view of a thin-film solar cell showing an embodiment of the present invention. A Mo film 17 serving as a back electrode is formed on a glass substrate 16 having minute irregularities on the surface, and Cu (In, Ga) Se 2 (a semiconductor thin film comprising Group I, Group III, and Group VI elements) is formed thereon. C
IGS) film 18 is formed. On the CIGS film, a semiconductor thin film CdS film 19 serving as a window layer and a ZnO film 20 and a transparent conductive film ITO film 21 serving as a surface electrode are sequentially formed. Here, Cu (In 0.8
Using Ga 0. 2) Se 2, has a thickness of 0.5 [mu] m. The thicknesses of the other layers are the same as in the first embodiment.
【００４０】図８に本構成の太陽電池の量子効率を示
す。比較のため、実施の形態１で述べたＣＩＧＳ膜の膜
厚０.５μｍの太陽電池の量子効率を破線で示してあ
る。基板のガラス表面に凹凸を設けることにより、各波
長での量子効率が改善されていることがわかる。この理
由は以下の通りである。ＣＩＧＳ膜で吸収されず透過し
た光はＭｏ膜に到達し反射される。この時、基板に凹凸
があるため、光は乱反射する。乱反射の場合は、鏡面反
射よりもＣＩＧＳ膜内で光が進む光路長が長くなり、光
が吸収される実質的な膜厚が増加することになる。従っ
て、ＣＩＧＳ膜を薄膜化しても十分に光が吸収されるこ
とになり、光電流が増加する。光電流の増加にともな
い、光起電圧（開放端電圧）も増加する。FIG. 8 shows the quantum efficiency of the solar cell having this configuration. For comparison, the broken line shows the quantum efficiency of the 0.5 μm-thick CIGS solar cell described in the first embodiment. It can be seen that the quantum efficiency at each wavelength is improved by providing irregularities on the glass surface of the substrate. The reason is as follows. Light that is not absorbed and transmitted by the CIGS film reaches the Mo film and is reflected. At this time, light is irregularly reflected because the substrate has irregularities. In the case of diffuse reflection, the optical path length in which light travels in the CIGS film becomes longer than in specular reflection, and the substantial film thickness in which light is absorbed increases. Therefore, even if the CIGS film is made thin, light is sufficiently absorbed, and the photocurrent increases. As the photocurrent increases, the photovoltaic voltage (open-circuit voltage) also increases.
【００４１】以上のように、基板に凹凸形状を設けるこ
とにより、ＣＩＧＳ膜を薄膜化しても光吸収量の減少は
少なくできるためエネルギー用太陽電池として必要とな
る変換効率が得られる。ここで、凹凸形状を有する基板
を用いる場合、裏面電極膜の被覆性が問題となる。凹凸
の高低差により裏面電極膜が被覆されない場合が生じ
る。ＣＩＧＳ太陽電池では、裏面電極のＭｏ膜の膜厚は
０.５〜２μｍ程度である。従って、十分な被覆性を得
るには凹凸の高低差は１０μｍ以下が妥当である。ま
た、凹凸の高低差が極端に小さいと乱反射の効果が生じ
ない。乱反射の効果を得るには凹凸の高低差としては
０.１μｍ以上が必要である。As described above, by providing the substrate with irregularities, even if the CIGS film is made thinner, the reduction in the amount of light absorption can be reduced, so that the conversion efficiency required for an energy solar cell can be obtained. Here, in the case of using a substrate having an uneven shape, the coverage of the back electrode film becomes a problem. There is a case where the back electrode film is not covered by the difference in height of the unevenness. In a CIGS solar cell, the thickness of the Mo film on the back electrode is about 0.5 to 2 μm. Therefore, in order to obtain sufficient coverage, it is appropriate that the height difference between the irregularities is 10 μm or less. Further, if the height difference between the irregularities is extremely small, the effect of irregular reflection does not occur. In order to obtain the effect of irregular reflection, the height difference of the unevenness needs to be 0.1 μm or more.
【００４２】また、平坦なガラス基板上に凹凸表面を有
する薄膜を形成しても同様な効果が得られる。例として
は、テクスチャー構造のＺｎＯ膜が挙げられる。ＺｎＯ
膜は製膜条件により凹凸表面を有する膜を形成できる。
この凹凸表面となるテクスチャー構造のＺｎＯ膜を基板
に堆積し、その上に裏面電極膜を形成すれば、同様な効
果が得られる。Similar effects can be obtained by forming a thin film having an uneven surface on a flat glass substrate. An example is a textured ZnO film. ZnO
As the film, a film having an uneven surface can be formed depending on film forming conditions.
The same effect can be obtained by depositing a ZnO film having a texture structure to be the uneven surface on a substrate and forming a back electrode film thereon.
【００４３】（実施の形態５）図９は本発明の一実施の
形態を示す薄膜太陽電池の断面模式図を示している。ガ
ラス基板２２上に裏面電極となるＭｏ膜２３を形成し、
その上にI族とIII族とVI族元素からなる半導体薄膜であ
るＣｕ(Ｉｎ,Ｇａ)Ｓｅ2（ＣＩＧＳ）膜２４を形成して
いる。このＣＩＧＳ膜の上に窓層となる半導体薄膜Ｃｄ
Ｓ膜２５とＺｎＯ膜２６を形成している。本実施の形態
では窓層となる半導体薄膜の上に表面に凹凸構造を有す
る透明電極膜ＺｎＯ：Ａｌ膜２７を形成した構成であ
る。ここでは、ＣＩＧＳ膜としてＣｕ(Ｉｎ0.8Ｇａ0.2)
Ｓｅ2を用い、その膜厚は０.５μｍである。また、Ｚｎ
Ｏ：Ａｌ膜の膜厚は約０.５μｍである。他の各層の膜
厚は、実施の形態１と同じである。(Embodiment 5) FIG. 9 is a schematic sectional view of a thin-film solar cell showing an embodiment of the present invention. A Mo film 23 serving as a back electrode is formed on a glass substrate 22,
A Cu (In, Ga) Se 2 (CIGS) film 24 which is a semiconductor thin film made of Group I, Group III and Group VI elements is formed thereon. A semiconductor thin film Cd serving as a window layer is formed on the CIGS film.
An S film 25 and a ZnO film 26 are formed. In this embodiment, a transparent electrode film ZnO: Al film 27 having an uneven structure on the surface is formed on a semiconductor thin film serving as a window layer. Here, Cu (In 0.8 Ga 0.2 ) is used as the CIGS film.
Se 2 is used, and its film thickness is 0.5 μm. Also, Zn
The thickness of the O: Al film is about 0.5 μm. The thicknesses of the other layers are the same as in the first embodiment.
【００４４】図１０に本構成の太陽電池の量子効率を示
す。比較のため、実施の形態１で述べたＣＩＧＳ膜の膜
厚０.５μｍの太陽電池の量子効率を破線で示してあ
る。透明導電膜の表面に凹凸を設けることにより、各波
長での量子効率が改善されていることがわかる。これ
は、太陽電池の表面となる透明導電膜の表面に凹凸形状
があるため、入射光が乱反射し、ＣＩＧＳ膜内を進む光
の光路長が長くなり、光が吸収される実質的な膜厚が増
加することによる。従って、ＣＩＧＳ膜を薄膜化しても
十分に光が吸収されることになり、光電流が増加する。
光電流の増加にともない、光起電圧（開放端電圧）も増
加する。FIG. 10 shows the quantum efficiency of the solar cell having this configuration. For comparison, the broken line shows the quantum efficiency of the 0.5 μm-thick CIGS solar cell described in the first embodiment. It can be seen that the quantum efficiency at each wavelength is improved by providing the unevenness on the surface of the transparent conductive film. This is because the surface of the transparent conductive film, which is the surface of the solar cell, has irregularities, so that incident light is irregularly reflected, the optical path length of light traveling in the CIGS film becomes longer, and a substantial film thickness that absorbs light is obtained. Is increased. Therefore, even if the CIGS film is made thin, light is sufficiently absorbed, and the photocurrent increases.
As the photocurrent increases, the photovoltaic voltage (open-circuit voltage) also increases.
【００４５】以上のように、太陽電池の表面層となる透
明導電膜に凹凸形状を設けることにより、ＣＩＧＳ膜を
薄膜化しても光吸収量の減少は少なくできるためエネル
ギー用太陽電池として必要となる変換効率が得られる。As described above, by providing the transparent conductive film serving as the surface layer of the solar cell with irregularities, even if the CIGS film is made thinner, the reduction in the amount of light absorbed can be reduced. Conversion efficiency is obtained.
【００４６】[0046]
【発明の効果】本発明の膜厚が１μｍ以下のI族とIII族
とVI族元素からなる半導体薄膜を光吸収層に用いる薄膜
太陽電池では、光吸収層形成の必要となる原材料の消費
量の減少とプロセス時間の短縮による製造に要するエネ
ルギーの減少により太陽電池の低コスト化を図ることが
できる。さらに、プロセス時間の短縮による量産性の向
上による低コスト化を図ることができる。According to the thin-film solar cell of the present invention, in which a semiconductor thin film having a film thickness of 1 μm or less and comprising a group I, group III, and group VI element is used as a light absorbing layer, the consumption of raw materials required for forming the light absorbing layer is reduced. As a result, the cost of the solar cell can be reduced due to the reduction in energy required for manufacturing due to the reduction in the process time and the process time. Furthermore, cost reduction can be achieved by improving mass productivity by shortening the process time.
【００４７】また、光吸収層の薄膜化では、裏面電極で
の再結合によるキャリアの消滅が問題となるが、本発明
では、この問題を解決する方法を提供している。In the case where the thickness of the light absorbing layer is reduced, the disappearance of carriers due to recombination at the back electrode becomes a problem. The present invention provides a method for solving this problem.
【００４８】本発明の第１の方法によれば、III族元素
としてＩｎ及びＧａを用いる光吸収層となるI族とIII族
とVI族元素からなる半導体薄膜において、ＧａのIII族
元素に占める割合が４０％以上である、すなわちＧａ/
（Ｉｎ＋Ｇａ）≧０.４である半導体薄膜か、あるいはV
I族元素としてＳｅ及びＳを用いる光吸収層となるI族と
III族とVI族元素からなる半導体薄膜において、ＳのVI
族元素に占める割合が４０％以上である、すなわちＳ/
（Ｓｅ＋Ｓ）≧０.４である半導体薄膜を光吸収層とし
て用いれば、前記半導体薄膜の拡散長が短いため裏面電
極での再結合の効果を低減できる。According to the first method of the present invention, Ga occupies the group III element of the semiconductor in the light absorbing layer using In and Ga as the group III element and comprising the group I, group III and group VI elements. The ratio is 40% or more, that is, Ga /
A semiconductor thin film satisfying (In + Ga) ≧ 0.4, or V
Group I to be a light absorbing layer using Se and S as Group I elements
In semiconductor thin films composed of Group III and Group VI elements,
Group element is 40% or more, that is, S /
If a semiconductor thin film satisfying (Se + S) ≧ 0.4 is used as the light absorbing layer, the effect of recombination at the back electrode can be reduced because the diffusion length of the semiconductor thin film is short.
【００４９】本発明の第２の方法によれば、III族元素
としてＩｎ及びＧａを用いる光吸収層となるI族とIII族
とVI族元素からなる半導体薄膜において、膜の厚さ方向
に対しＩｎとＧａの組成比の相対値が変化する分布を有
する半導体薄膜かあるいはVI族元素としてＳｅ及びＳを
用いる光吸収層となるI族とIII族とVI族元素からなる半
導体薄膜において、膜の厚さ方向に対しＳｅとＳの組成
比の相対値が変化する分布を有する半導体薄膜を光吸収
層に用いれば、裏面電極付近に伝導帯におけるエネルギ
ー障壁を形成できるため、裏面電極方向へと移動する光
励起キャリアが反射されることから裏面電極での再結合
によるキャリアの消滅を低減できる。さらに、本発明に
おいては、III族元素としてＩｎ及びＧａを用いる光吸
収層となるI族とIII族とVI族元素からなる半導体薄膜の
膜の厚さ方向に対し、III族元素中に占めるＧａの組成
比が裏面電極膜側からｐｎ接合面となる窓層側へと減少
する分布を有する半導体薄膜か、あるいはVI族元素とし
てＳｅ及びＳを用いる光吸収層となるI族とIII族とVI族
元素からなる半導体薄膜の膜の厚さ方向に対し、VI族元
素中に占めるＳの組成比が裏面電極膜側からｐｎ接合面
となる窓層側へと減少する分布を有する半導体薄膜を光
吸収層に用いれば、光吸収層内部に電界が生じ、その電
界により生成されたキャリアはｐｎ接合面へと移動する
ことになる。従って、裏面電極での再結合によるキャリ
アの消滅を低減できる。According to the second method of the present invention, in a semiconductor thin film comprising a group I, a group III and a group VI element serving as a light absorption layer using In and Ga as a group III element, In a semiconductor thin film having a distribution in which the relative value of the composition ratio of In and Ga changes, or in a semiconductor thin film made of Group I, Group III, and Group VI elements serving as a light absorption layer using Se and S as Group VI elements, If a semiconductor thin film having a distribution in which the relative value of the composition ratio of Se and S changes with respect to the thickness direction is used for the light absorbing layer, an energy barrier in the conduction band can be formed near the back electrode, so that it moves toward the back electrode. Since the excited photoexcited carriers are reflected, the disappearance of carriers due to recombination at the back electrode can be reduced. Further, in the present invention, in the thickness direction of a semiconductor thin film comprising a group I, a group III and a group VI element, which is a light absorption layer using In and Ga as a group III element, Semiconductor thin film having a distribution in which the composition ratio decreases from the back electrode film side to the window layer side serving as the pn junction surface, or a group I, group III, and VI serving as a light absorbing layer using Se and S as group VI elements A semiconductor thin film having a distribution in which the composition ratio of S in the group VI element decreases from the back electrode film side to the window layer side to be a pn junction surface with respect to the thickness direction of the semiconductor thin film made of the group III element. When used for the absorption layer, an electric field is generated inside the light absorption layer, and carriers generated by the electric field move to the pn junction surface. Therefore, the disappearance of carriers due to recombination at the back electrode can be reduced.
【００５０】本発明の第３の方法によれば、電極となる
Ｍｏ膜と光吸収層となるＩ族とIII族とVI族元素からな
る半導体薄膜の間に、ＭｏとVI族元素の化合物層を形成
すると、ＭｏとVI族元素の化合物層と光吸収層で多数キ
ャリア濃度が異なることによる内部電界が生じ、少数キ
ャリアはこの電界により反射されｐｎ接合面へと移動す
る。従って、裏面電極での再結合によるキャリアの消滅
を低減できる。According to the third method of the present invention, a compound layer of Mo and a group VI element is provided between a Mo film serving as an electrode and a semiconductor thin film comprising a group I, group III and group VI element serving as a light absorbing layer. Is formed, an internal electric field is generated due to the difference in the majority carrier concentration between the compound layer of the Mo and group VI elements and the light absorbing layer, and the minority carriers are reflected by this electric field and move to the pn junction surface. Therefore, the disappearance of carriers due to recombination at the back electrode can be reduced.
【００５１】また、光吸収層を薄膜化すると光吸収量の
低減という問題がある。本発明はこの問題を解決する方
法も提供している。Further, when the light absorbing layer is made thin, there is a problem that the amount of light absorption is reduced. The present invention also provides a method for solving this problem.
【００５２】本発明の第４の方法によれば、表面が凹凸
形態である基体を用いると、光吸収層で十分吸収されず
に透過し、裏面電極に到達した光は乱反射する。乱反射
すると光吸収層内部を伝搬する光の光路長が長くなり、
光が吸収される実質的な膜厚が増加する。従って、光吸
収層の薄膜化による光吸収量の低減を防ぐことができ
る。According to the fourth method of the present invention, when a substrate having an uneven surface is used, the light is transmitted without being sufficiently absorbed by the light absorbing layer, and the light reaching the back electrode is irregularly reflected. Diffuse reflection increases the optical path length of light propagating inside the light absorbing layer,
The substantial film thickness in which light is absorbed increases. Therefore, it is possible to prevent a reduction in the amount of light absorption due to the thinning of the light absorption layer.
【００５３】本発明の第５の方法によれば、光が入射す
る面の表面が凹凸形態であると、入射した光は乱反射
し、光吸収層内部を伝搬する光の光路長が長くなり、光
が吸収される実質的な膜厚が増加する。従って、光吸収
層の薄膜化による光吸収量の低減を防ぐことができる。According to the fifth method of the present invention, if the surface on which the light is incident is irregular, the incident light is irregularly reflected, and the optical path length of the light propagating inside the light absorbing layer becomes longer. The substantial film thickness in which light is absorbed increases. Therefore, it is possible to prevent a reduction in the amount of light absorption due to the thinning of the light absorption layer.
【００５４】以上から、本発明の薄膜太陽電池の構成を
用いるならば、光吸収層の薄膜化による変換効率の低減
を防ぐことが可能となる。従って、原材料の消費量が少
なく生産エネルギーが小さいエネルギー用太陽電池を大
量に提供できる。As described above, if the structure of the thin-film solar cell of the present invention is used, it is possible to prevent the conversion efficiency from being reduced by reducing the thickness of the light absorbing layer. Therefore, it is possible to provide a large amount of energy solar cells with low consumption of raw materials and low production energy.
【図１】本発明の１実施の形態である薄膜太陽電池の断
面模式図FIG. 1 is a schematic cross-sectional view of a thin-film solar cell according to an embodiment of the present invention.
【図２】本発明の薄膜太陽電池の光吸収層の膜厚に対す
る太陽電池特性の変化を示す図FIG. 2 is a diagram showing changes in solar cell characteristics with respect to the thickness of a light absorbing layer of the thin-film solar cell of the present invention.
【図３】本発明の薄膜太陽電池の波長に対する量子効率
を示す図FIG. 3 is a diagram showing quantum efficiency with respect to wavelength of the thin-film solar cell of the present invention.
【図４】本発明の薄膜太陽電池の異なる光吸収層に対す
る太陽電池特性の変化を示す図FIG. 4 is a diagram showing changes in solar cell characteristics for different light absorbing layers of the thin-film solar cell of the present invention.
【図５】本発明の１実施の形態である薄膜太陽電池の断
面模式図FIG. 5 is a schematic cross-sectional view of a thin-film solar cell according to an embodiment of the present invention.
【図６】本発明の薄膜太陽電池のＭｏＳｅ２層の膜厚に
対する太陽電池特性の変化を示す図FIG. 6 is a diagram showing a change in solar cell characteristics with respect to the thickness of the MoSe2 layer of the thin-film solar cell of the present invention.
【図７】本発明の１実施の形態である薄膜太陽電池の断
面模式図FIG. 7 is a schematic cross-sectional view of a thin-film solar cell according to an embodiment of the present invention.
【図８】本発明の薄膜太陽電池の波長に対する量子効率
を示す図FIG. 8 is a diagram showing quantum efficiency with respect to wavelength of the thin-film solar cell of the present invention.
【図９】本発明の１実施の形態である薄膜太陽電池の断
面模式図FIG. 9 is a schematic cross-sectional view of a thin-film solar cell according to an embodiment of the present invention.
【図１０】本発明の薄膜太陽電池の波長に対する量子効
率を示す図FIG. 10 is a diagram showing quantum efficiency with respect to wavelength of the thin-film solar cell of the present invention.
１ ガラス基板 ２ Ｍｏ膜（裏面電極膜） ３ Ｃｕ(Ｉｎ,Ｇａ)Ｓｅ2膜（光吸収層） ４ ＣｄＳ膜（窓層） ５ ＺｎＯ膜（窓層） ６ ＩＴＯ膜（透明電極膜） ７ ＭｇＦ2膜（反射防止膜） ８ ガラス基板 ９ Ｍｏ膜（裏面電極膜） １０ ＭｏＳｅ2膜 １１ Ｃｕ(Ｉｎ,Ｇａ)Ｓｅ2膜（光吸収層） １２ ＣｄＳ膜（窓層） １３ ＺｎＯ膜（窓層） １４ ＩＴＯ膜（透明電極膜） １５ ＭｇＦ２膜（反射防止膜） １６ 表面が凹凸形態であるガラス基板 １７ Ｍｏ膜（裏面電極膜） １８ Ｃｕ(Ｉｎ,Ｇａ)Ｓｅ2膜（光吸収層） １９ ＣｄＳ膜（窓層） ２０ ＺｎＯ膜（窓層） ２１ ＩＴＯ膜（透明電極膜） ２２ ガラス基板 ２３ Ｍｏ膜（裏面電極膜） ２４ Ｃｕ(Ｉｎ,Ｇａ)Ｓｅ2膜（光吸収層） ２５ ＣｄＳ膜（窓層） ２６ ＺｎＯ膜（窓層） ２７ 凹凸表面を有するＺｎＯ：Ａｌ膜（透明導電膜）Reference Signs List 1 glass substrate 2 Mo film (backside electrode film) 3 Cu (In, Ga) Se 2 film (light absorbing layer) 4 CdS film (window layer) 5 ZnO film (window layer) 6 ITO film (transparent electrode film) 7 MgF 2 film (anti-reflection film) 8 glass substrate 9 Mo film (backside electrode film) 10 MoSe 2 film 11 Cu (In, Ga) Se 2 film (light absorption layer) 12 CdS film (window layer) 13 ZnO film (window layer) 14) ITO film (transparent electrode film) 15 MgF2 film (anti-reflection film) 16 Glass substrate having an uneven surface 17 Mo film (back surface electrode film) 18 Cu (In, Ga) Se 2 film (light absorbing layer) 19 CdS film (window layer) 20 ZnO film (window layer) 21 ITO film (transparent electrode film) 22 glass substrate 23 Mo film (backside electrode film) 24 Cu (In, Ga) Se 2 film (light absorbing layer) 25 CdS film (Window layer) 26 ZnO film (Window layer) 27 Has uneven surface ZnO: Al film (transparent conductive film)
───────────────────────────────────────────────────── フロントページの続き (72)発明者 小原 直樹 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Naoki Ohara 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.
Claims (14)
素からなる半導体薄膜を光吸収層に用いる薄膜太陽電
池。1. A thin-film solar cell in which a semiconductor thin film having a film thickness of 1 μm or less and comprising a group I, group III or group VI element is used as a light absorbing layer.
光吸収層となるI族とIII族とVI族元素からなる半導体薄
膜において、ＧａのIII族元素に占める割合が４０％以
上である半導体薄膜を用いる請求項１記載の薄膜太陽電
池。2. A semiconductor thin film comprising a group I, a group III and a group VI element serving as a light absorbing layer using In and Ga as a group III element, wherein Ga accounts for at least 40% of the group III element. The thin-film solar cell according to claim 1, wherein
光吸収層となるI族とIII族とVI族元素からなる半導体薄
膜において、膜の厚さ方向に対しＩｎとＧａの組成比の
相対値が変化する分布を有する半導体薄膜を用いる請求
項１記載の薄膜太陽電池。3. A relative value of a composition ratio of In and Ga in a thickness direction of a semiconductor thin film comprising a group I, a group III, and a group VI element, which is a light absorption layer using In and Ga as a group III element. The thin-film solar cell according to claim 1, wherein a semiconductor thin film having a distribution in which is changed.
層となる半導体薄膜を積層してなる構成を含む薄膜太陽
電池において、III族元素としてＩｎ及びＧａを用いる
光吸収層となるI族とIII族とVI族元素からなる半導体薄
膜の膜の厚さ方向に対し、III族元素中に占めるＧａの
組成比が電極膜側から窓層側へと減少する分布を有する
半導体薄膜を用いる請求項３記載の薄膜太陽電池。4. In a thin-film solar cell including a structure in which an electrode film, a semiconductor thin film serving as a light absorbing layer, and a semiconductor thin film serving as a window layer are laminated, I serving as a light absorbing layer using In and Ga as Group III elements. Use a semiconductor thin film that has a distribution in which the composition ratio of Ga in the group III element decreases from the electrode film side to the window layer side in the thickness direction of the semiconductor thin film composed of group III, group III, and group VI elements The thin-film solar cell according to claim 3.
収層となるI族とIII族とVI族元素からなる半導体薄膜に
おいて、ＳのVI族元素に占める割合が４０％以上である
半導体薄膜を用いる請求項１記載の薄膜太陽電池。5. A semiconductor thin film comprising a group I, a group III and a group VI element serving as a light absorption layer using Se and S as group VI elements, wherein S accounts for at least 40% of the group VI element. The thin-film solar cell according to claim 1, wherein
収層となるI族とIII族とVI族元素からなる半導体薄膜に
おいて、膜の厚さ方向に対しＳｅとＳの組成比の相対値
が変化する分布を有する半導体薄膜を用いる請求項１記
載の薄膜太陽電池。6. A relative value of a composition ratio of Se and S in a thickness direction of a semiconductor thin film comprising a group I, a group III, and a group VI element serving as a light absorption layer using Se and S as group VI elements. The thin-film solar cell according to claim 1, wherein a semiconductor thin film having a distribution in which is changed.
層となる半導体薄膜を積層してなる薄膜太陽電池におい
て、VI族元素としてＳｅ及びＳを用いる光吸収層となる
I族とIII族とVI族元素からなる半導体薄膜の膜の厚さ方
向に対し、VI族元素中に占めるＳの組成比が電極膜側か
ら窓層側へと増加する分布を有する半導体薄膜を用いる
請求項６記載の薄膜太陽電池。7. In a thin-film solar cell in which an electrode film, a semiconductor thin film serving as a light absorbing layer, and a semiconductor thin film serving as a window layer are stacked, the light absorbing layer uses Se and S as Group VI elements.
A semiconductor thin film having a distribution in which the composition ratio of S in the group VI element increases from the electrode film side to the window layer side in the thickness direction of the semiconductor thin film composed of the group I, group III, and group VI elements. The thin-film solar cell according to claim 6, which is used.
合物層、請求項１〜７のいずれかに記載の半導体薄膜を
積層してなる構成を含む薄膜太陽電池。8. A thin-film solar cell comprising a structure in which a Mo film serving as an electrode, a compound layer of Mo and a group VI element, and the semiconductor thin film according to claim 1 are stacked.
ｍ以下である請求項８記載の薄膜太陽電池。9. The thickness of a compound layer of Mo and a group VI element is 1 μm.
9. The thin-film solar cell according to claim 8, which is not more than m.
求項１〜９のいずれかに記載の薄膜太陽電池。10. The thin-film solar cell according to claim 1, wherein a substrate having an uneven surface is used.
のいずれかから構成される基体を用いる請求項１０記載
の薄膜太陽電池。11. The thin-film solar cell according to claim 10, wherein a base made of glass, a sintered body, or a metal body is used.
を堆積してなる基体を用いる請求項１０記載の薄膜太陽
電池。12. The thin-film solar cell according to claim 10, wherein a base is formed by depositing a thin film having an uneven shape on a flat base.
ｍ以上で１０μｍ以下である基体を用いる請求項１０記
載の薄膜太陽電池。13. The height difference between the peaks and valleys of the irregularities is 0.1 μm.
The thin-film solar cell according to claim 10, wherein a substrate having a size of not less than m and not more than 10 μm is used.
る請求項１〜９のいずれかに記載の薄膜太陽電池。14. The thin-film solar cell according to claim 1, wherein the surface on which light is incident has an uneven shape.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9325801A JPH11163376A (en) | 1997-11-27 | 1997-11-27 | Thin-film solar cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9325801A JPH11163376A (en) | 1997-11-27 | 1997-11-27 | Thin-film solar cell |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11163376A true JPH11163376A (en) | 1999-06-18 |
Family
ID=18180754
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9325801A Withdrawn JPH11163376A (en) | 1997-11-27 | 1997-11-27 | Thin-film solar cell |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11163376A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007086521A1 (en) * | 2006-01-30 | 2007-08-02 | Honda Motor Co., Ltd. | Solar cell and its manufacturing method |
| JP2009289955A (en) * | 2008-05-29 | 2009-12-10 | Honda Motor Co Ltd | Solar cell, and manufacturing method of solar cell |
| KR101283106B1 (en) * | 2011-11-21 | 2013-07-05 | 엘지이노텍 주식회사 | Solar cell and method for fabricating unsing the same |
| JP2014120628A (en) * | 2012-12-17 | 2014-06-30 | Rohm Co Ltd | Photoelectric conversion device and method of manufacturing the same |
| JP2015162632A (en) * | 2014-02-28 | 2015-09-07 | セイコーエプソン株式会社 | Photoelectric conversion device, method of manufacturing photoelectric conversion device, and electronic apparatus |
| WO2022138623A1 (en) * | 2020-12-21 | 2022-06-30 | 出光興産株式会社 | Electrode structure for solar cell and manufacturing method therefor |
-
1997
- 1997-11-27 JP JP9325801A patent/JPH11163376A/en not_active Withdrawn
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007086521A1 (en) * | 2006-01-30 | 2007-08-02 | Honda Motor Co., Ltd. | Solar cell and its manufacturing method |
| JP2007201304A (en) * | 2006-01-30 | 2007-08-09 | Honda Motor Co Ltd | Solar cell and its manufacturing method |
| JP2009289955A (en) * | 2008-05-29 | 2009-12-10 | Honda Motor Co Ltd | Solar cell, and manufacturing method of solar cell |
| KR101283106B1 (en) * | 2011-11-21 | 2013-07-05 | 엘지이노텍 주식회사 | Solar cell and method for fabricating unsing the same |
| JP2014120628A (en) * | 2012-12-17 | 2014-06-30 | Rohm Co Ltd | Photoelectric conversion device and method of manufacturing the same |
| JP2015162632A (en) * | 2014-02-28 | 2015-09-07 | セイコーエプソン株式会社 | Photoelectric conversion device, method of manufacturing photoelectric conversion device, and electronic apparatus |
| WO2022138623A1 (en) * | 2020-12-21 | 2022-06-30 | 出光興産株式会社 | Electrode structure for solar cell and manufacturing method therefor |
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