JPH0642351Y2 - Photovoltaic device - Google Patents

Description

【考案の詳細な説明】 （イ）産業上の利用分野 本考案は光エネルギを直接電気エネルギに変換する光起
電力装置に関する。DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a photovoltaic device for directly converting light energy into electric energy.

（ロ）従来の技術 アモルフアスシリコンなどの膜状の半導体層を光活性領
域とする光起電力装置は、半導体層が膜状であるために
原理的に大面積化が容易に実現でき、その大面積化が低
コスト化に寄与する。(B) Conventional technology In a photovoltaic device using a film-shaped semiconductor layer such as amorphous silicon as a photoactive region, it is possible to easily realize a large area in principle because the semiconductor layer is film-shaped. Larger area contributes to lower costs.

一般的に光起電力装置を大面積化すると、光電変換効率
が低下する。斯る光電変換効率の低下の一つの要因とし
て光入射側に設けられ受光面電極を構成する透光性導電
層のシート抵抗による電力損失がある。Generally, when the area of a photovoltaic device is increased, the photoelectric conversion efficiency is reduced. One of the causes of such a decrease in photoelectric conversion efficiency is power loss due to the sheet resistance of the translucent conductive layer provided on the light incident side and forming the light-receiving surface electrode.

この透光性導電層のシート抵抗を低減させる一つの方法
として、受光面電極を上記透光性導電層に加え該導電層
より良導電体から成り、概ね全域に渡って光伝搬路を残
して延在する格子状の集電極を設ける工夫がなされてい
る。As one method of reducing the sheet resistance of the transparent conductive layer, a light-receiving surface electrode is added to the transparent conductive layer and is made of a conductor better than the conductive layer, leaving a light propagation path over almost the entire area. A device for providing an extending grid-shaped collecting electrode has been made.

然し乍ら、斯る構造によれば電力損失対策については有
効な手段となり得るものの、集電極が半導体層を貫通し
たり、また集電極の存在により凸状となった部分上の半
導体層にピンホールが発生しやすくシヤント抵抗の低下
を招く。However, although such a structure can be an effective measure against power loss, the collector electrode penetrates the semiconductor layer, and pinholes are formed in the semiconductor layer on the convex portion due to the presence of the collector electrode. It tends to occur and causes a decrease in shunt resistance.

特開昭59−117177号公報に開示された先行技術は、上記
集電極が半導体層を貫通し裏面電極層と電気的に接触す
る短絡事故に鑑み、半導体層を挟んで集電極と対向する
部分には裏面電極層を設けず半導体層を露出せしめる構
造を提案している。この様に、集電極と対向する部分に
は裏面電極層を設けず切欠いた構造とするために、裏面
電極層を形成時切欠き部分を金属マスクで覆い直接その
構造にパターニングするマスク蒸着法と、裏面電極層を
全面に配置後切欠き部分の裏面電極層部分をエツチング
により除去するフオトリソグラフイ法の何れかが一般的
に用いられる。In the prior art disclosed in JP-A-59-117177, in consideration of a short circuit accident in which the collector electrode penetrates the semiconductor layer and electrically contacts the back electrode layer, a portion facing the collector electrode across the semiconductor layer is provided. Proposes a structure in which the back electrode layer is not provided and the semiconductor layer is exposed. In this way, in order to have a notched structure without providing a back electrode layer in the portion facing the collector electrode, a mask vapor deposition method of directly covering the notched portion with a metal mask when forming the back electrode layer and patterning in that structure Any of the photolithographic methods in which the rear surface electrode layer is disposed on the entire surface and then the rear surface electrode layer portion of the cutout portion is removed by etching is generally used.

然るに、実際上述の法により裏面電極層を製造する場
合、以下のような欠点がある。即ち、マスク蒸着法を用
いる場合、切欠き部分を金属マスクで覆われなければな
らないものの、覆う切欠き部分は集電極と対向する部分
であり、斯る集電極は受光面中に占める割合が大きくな
ると光入射を減少させるために幅狭まなパターン構造と
なっているので、斯るパターン構造をマスクに実現する
と機械的強度の欠けたものとなる。従って、マスク自体
が耐久性の乏しいものとなり多数回に渡ってマスクを使
用することができない。However, when the back electrode layer is actually manufactured by the above method, there are the following drawbacks. That is, when the mask vapor deposition method is used, the cutout portion must be covered with a metal mask, but the cover cutout portion is a portion facing the collector electrode, and such a collector electrode has a large proportion in the light receiving surface. In this case, since the pattern structure has a narrow width in order to reduce the incidence of light, if such a pattern structure is realized as a mask, the mechanical strength will be insufficient. Therefore, the mask itself has poor durability, and the mask cannot be used many times.

また、フオトリソグラフイ法にあってはウエツトプロセ
スを含むために半導体層にピンホールが発生している
と、このピンホールを通してエツチヤント等が半導体層
の受光面側に浸透し半導体層の剥離の原因となったり、
剥離を招かないまでも信頼性の低下につながる。Further, in the photolithography method, if a pinhole is generated in the semiconductor layer because it includes a wet process, an etchant or the like penetrates into the light-receiving surface side of the semiconductor layer through the pinhole and peels off the semiconductor layer. Cause
Even if it does not cause peeling, it leads to a decrease in reliability.

（ハ）考案が解決しようとする問題点 本考案は上述の如く受光面電極を透光性導電層と集電極
によって構成したときに生じる上述のマスクの耐久性の
欠如や半導体層の剥離・信頼性の低下を解決しようとす
るものである。(C) Problems to be solved by the present invention The present invention has the above-mentioned lack of durability of the mask and peeling / reliability of the semiconductor layer, which occurs when the light-receiving surface electrode is composed of the translucent conductive layer and the collecting electrode as described above. It aims to solve the decline in sex.

（ニ）問題点を解決するための手段 本考案は上記問題点を解決するために、半導体層を介し
て集電極と対向する裏面電極材料をその集電極のほぼ輪
郭に沿って切欠くことで電気的に分断された、集電極背
面に配置された表面層と上記裏面電極材料のその他の部
分から成る裏面電極層とからなることを特徴とする。(D) Means for Solving the Problems In order to solve the above problems, the present invention provides a back electrode material facing a collector electrode through a semiconductor layer by notching along a substantially contour of the collector electrode. It is characterized in that it is composed of an electrically separated front surface layer disposed on the back surface of the collecting electrode and a back surface electrode layer formed of the other part of the back surface electrode material.

（ホ）作用 上述の如く半導体層を介して集電極と対向する部分の裏
面電極材料を上記集電極のほぼ輪郭に沿って切欠くこと
によって、集電極対向部分の全域に渡る半導体層部分の
露出は回避される。(E) Action As described above, the back surface electrode material of the portion facing the collector electrode via the semiconductor layer is cut out along substantially the contour of the collector electrode to expose the semiconductor layer portion over the entire area facing the collector electrode. Is avoided.

（ヘ）実施例 第１図及び第２図は本考案光起電力装置を示し、第１図
は平面図、第２図は第１図に於けるＸ−Ｘ′線断面図で
あり、（１）は受光面となるガラス等の透光性の絶縁基
板、（２）は該基板（１）上に設けられた受光面電極層
で、該受光面電極層（２）は酸化スズや酸化インジウム
等のシート抵抗数10Ω／口の透光性導電層（３）と、該
導電層（３）より導電率の高いアルミニウム、金、銀等
の金属製良導電体から成る格子状集電極（４）と、から
構成され受光面電極層（２）全体のシート抵抗を低減せ
しめている。そして、上記集電体（４）は光の伝搬路を
あまり遮ることなく配挿せしめられることが肝要であ
り、有効受光面積の５〜10％を占有すべく概ね全域に渡
って光伝搬路を残して延在している。(F) Embodiment FIG. 1 and FIG. 2 show a photovoltaic device of the present invention, FIG. 1 is a plan view, and FIG. 2 is a sectional view taken along line XX ′ in FIG. 1) is a light-transmissive insulating substrate such as glass serving as a light-receiving surface, (2) is a light-receiving surface electrode layer provided on the substrate (1), and the light-receiving surface electrode layer (2) is tin oxide or oxide. A grid-shaped collector electrode composed of a light-transmissive conductive layer (3) having a sheet resistance of 10 Ω / port such as indium and a good conductor made of a metal such as aluminum, gold, or silver having a higher conductivity than the conductive layer (3) ( 4) and the sheet resistance of the entire light-receiving surface electrode layer (2) is reduced. It is important that the current collector (4) is installed without blocking the light propagation path so much that the light propagation path is spread over almost the entire area so as to occupy 5 to 10% of the effective light receiving area. It has been extended and left.

（５）は上記受光面電極層（２）上に被着された例えば
非晶質シリコンのホモ接合や非晶質シリコンカーバイド
とのヘテロ接合等を備えた厚み１μｍ以下の膜状半導体
層で、該半導体層（５）は光照射により発電に寄与する
電子及びまたは正孔を発生する光活性層を含み、具体的
には受光面側からＰ型層、Ｉ型層及びＮ型層の膜面に平
行なPIN接合を持ち、斯る構造はシラン、ジシラン、４
フツ化シリコンなどのシリコン化合物ガスに適宜Ｐ型・
Ｎ型決定不純物ガスを含む雰囲気中でのプラズマ分解法
や光分解法により形成される。(5) is a film-like semiconductor layer having a thickness of 1 μm or less, which is deposited on the light-receiving surface electrode layer (2) and has, for example, a homojunction of amorphous silicon or a heterojunction with amorphous silicon carbide, The semiconductor layer (5) includes a photoactive layer that generates electrons and / or holes that contribute to power generation by light irradiation, and specifically, the film surfaces of a P-type layer, an I-type layer, and an N-type layer from the light-receiving surface side. With a PIN junction parallel to, such structures are silane, disilane, 4
Appropriate P type for silicon compound gas such as silicon fluoride
It is formed by a plasma decomposition method or a photo decomposition method in an atmosphere containing an N-type determining impurity gas.

（６）は上記半導体層（５）上に被着されたオーミツク
金属製の裏面電極材料で、該裏面電極材料（６）は半導
体層（５）の裏面全域に蒸着等により被着形成された
後、半導体層（５）を挟んで集電極（４）と対向する表
面層（6a）が上記集電極（４）のほぼ輪郭に沿って切欠
かれ、集電極（４）背面の表面層（6a）と裏面電極層
（6b）、即ち有効部分とを電気的に分断する。斯る表面
層（6a）と裏面電極層（6b）の電気的分断は、集電極
（４）の輪郭より僅かに外側をその輪郭に沿って該裏面
電極材料（６）を除去するに十分なエネルギ密度を持つ
レーザビームを照射することにより容易に行なうことが
できる。このレーザビームの照射による分断はマスク蒸
着法のようなマスクを必要とせず、フオトリソグラフイ
法の如くウエツトプロセスを経ないために従来の問題点
は発生しない。(6) is a back electrode material made of ohmic metal deposited on the semiconductor layer (5), and the back electrode material (6) is deposited on the entire back surface of the semiconductor layer (5) by vapor deposition or the like. Then, the surface layer (6a) facing the collecting electrode (4) with the semiconductor layer (5) interposed therebetween is cut out along substantially the contour of the collecting electrode (4), and the surface layer (6a) on the back surface of the collecting electrode (4) is cut. ) And the back electrode layer (6b), that is, the effective portion, are electrically separated. The electrical separation between the surface layer (6a) and the back electrode layer (6b) is sufficient to remove the back electrode material (6) along the contour slightly outside the contour of the collector electrode (4). It can be easily performed by irradiating a laser beam having an energy density. The division by the irradiation of the laser beam does not require a mask unlike the mask vapor deposition method, and does not require a wet process unlike the photolithography method, so that the conventional problems do not occur.

一方、表面層（6a）と裏面電極層（6b）の電気的分断を
行なう別の方法としてフオトリソグラフイ法が存在す
る。従来に於けるフオトリソグラフイ法の欠点は集電極
（４）背面の表面層（6a）を本実施例の如く残存させる
ことなくエツチング除去していたために、露出した半導
体層にピンホールが形成されているとそのピンホールか
らエツチヤント等が浸透し半導体層（５）の剥離や信頼
性の低下を招いていた。ところが、この実施例の如く本
考案にあってはピンホールの発し易い集電極（４）背面
の半導体層（５）は露出することなく表面層（6a）によ
り被覆されエツチヤント等との接触が防止されているの
で、斯るフオトリソグラフイ法も用いることも可能とな
る。On the other hand, there is a photolithography method as another method for electrically separating the surface layer (6a) and the back electrode layer (6b). A drawback of the conventional photolithography method is that the surface layer (6a) on the back surface of the collector electrode (4) is removed by etching without leaving it as in the present embodiment, so that a pinhole is formed in the exposed semiconductor layer. Then, etchant or the like penetrates through the pinholes, causing peeling of the semiconductor layer (5) and deterioration of reliability. However, in the present invention as in this embodiment, the semiconductor layer (5) on the back surface of the collector electrode (4) where pinholes are likely to occur is not exposed and is covered with the surface layer (6a) to prevent contact with an etchant or the like. Therefore, it is possible to use such a photolithography method as well.

（ト）考案の効果 本考案光起電力装置は以上の説明から明らかな如く、半
導体層を介して集電極と対向する部分の裏面電極材料を
上記集電極のほぼ輪郭に沿って切欠くことによって、集
電極対向部分の全域に渡る半導体層部分の露出は回避さ
れるので、斯る裏面電極材料の切欠き加工にレーザビー
ムを用いることができ、また従来の欠点を招くことなく
フオトリソグラフイ法を利用することも可能となり、製
造簡単にして受光面電極のシート抵抗の低減化を実現し
得る。(G) Effect of the Invention As is apparent from the above description, the photovoltaic device of the present invention is constructed by notching the backside electrode material in the portion facing the collector electrode through the semiconductor layer substantially along the contour of the collector electrode. Since the exposure of the semiconductor layer portion over the entire area facing the collector electrode is avoided, the laser beam can be used for the notch processing of the back electrode material, and the photolithography method can be used without causing the conventional defects. It is also possible to utilize, and the sheet resistance of the light-receiving surface electrode can be reduced by simplifying the manufacturing.

【図面の簡単な説明】[Brief description of drawings]

図は本考案光起電力装置の一実施例を示し、第１図は光
入射方向に対し逆方向から臨んだ平面図、第２図は第１
図に於けるＸ−Ｘ′線断面図、であって、（１）は絶縁
基板、（３）は透光性導電層、（４）は集電極、（５）
は半導体層、（６）は裏面電極材料、（6a）は表面層、
（6b）は裏面電極層、を夫々示している。FIG. 1 shows an embodiment of the photovoltaic device of the present invention, FIG. 1 is a plan view from the opposite direction to the light incident direction, and FIG.
FIG. 4 is a cross-sectional view taken along line XX ′ in the figure, where (1) is an insulating substrate, (3) is a translucent conductive layer, (4) is a collector electrode, and (5).
Is a semiconductor layer, (6) is a back electrode material, (6a) is a front layer,
(6b) shows the back electrode layer, respectively.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 【請求項１】受光面となる透光性の絶縁基板上に、透光
性導電層、光活性領域を含む膜状の半導体層及び裏面電
極層を積層せしめて成る光起電力装置に於いて、 上記透光性導電層と半導体層との間に、上記導電層より
良導電体から成りその概ね全域に渡って光伝搬路を残す
べく延在するように配挿された集電極と、上記透光性導
電層と該集電極とを覆うように形成された上記半導体層
と、該半導体層上の裏面であって、該半導体層を介して
夫々対向する、該集電極の部分から該透光性導電層の部
分にまで連なって形成された裏面電極材料のうち上記半
導体層を介して上記集電極と対向する部分を該集電極の
ほぼ輪郭に沿って切欠くことで電気的に分断された、該
集電極背面に配置される表面層と、上記裏面電極材料の
その他の部分から成る上記裏面電極層と、からなること
を特徴とする光起電力装置。1. A photovoltaic device comprising a translucent conductive layer, a film-like semiconductor layer containing a photoactive region, and a back electrode layer laminated on a translucent insulating substrate serving as a light-receiving surface. A collector electrode disposed between the translucent conductive layer and the semiconductor layer, the collector electrode being made of a good conductor than the conductive layer and extending so as to leave a light propagation path over substantially the entire area thereof; The semiconductor layer formed so as to cover the translucent conductive layer and the collecting electrode, and the rear surface of the semiconductor layer, which faces the collecting electrode from the portion of the collecting electrode facing each other through the semiconductor layer. Of the back surface electrode material formed so as to extend to the portion of the photoconductive layer, the portion facing the collecting electrode through the semiconductor layer is cut out substantially along the contour of the collecting electrode to be electrically separated. In addition, a surface layer disposed on the back surface of the collector electrode and an upper portion composed of the other part of the back electrode material. A backside electrode layer, and a photovoltaic device.