JP4379557B2

JP4379557B2 - Thin film solar cell manufacturing method and manufacturing apparatus

Info

Publication number: JP4379557B2
Application number: JP2000339508A
Authority: JP
Inventors: 敏夫 ▲浜▼
Original assignee: Fuji Electric Systems Co Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 2000-11-07
Filing date: 2000-11-07
Publication date: 2009-12-09
Anticipated expiration: 2020-11-07
Also published as: JP2002151714A

Description

【０００１】
【発明の属する技術分野】
この発明は、ユニットセルを複数個直列接続した薄膜太陽電池の製造方法および製造装置に関する。
【０００２】
【従来の技術】
現在、環境保護の立場から、クリーンなエネルギーの研究開発が進められている。中でも、太陽電池はその資源（太陽光）が無限であること、無公害であることから注目を集めている。
【０００３】
同一基板上に形成された複数の太陽電池素子が、直列接続されてなる太陽電池（光電変換装置）の代表例は、薄膜太陽電池である。
【０００４】
薄膜太陽電池は、薄型で軽量、製造コストの安さ、大面積化が容易であることなどから、今後の太陽電池の主流となると考えられ、電力供給用以外に、建物の屋根や窓などにとりつけて利用される業務用，一般住宅用にも需要が広がってきている。
【０００５】
従来の薄膜太陽電池はガラス基板を用いているものが一般的であった。近年、軽量化、施工性、量産性においてプラスチックフィルムを用いたフレキシブルタイプの太陽電池の研究開発が進められ実用化されている。さらに、フレキシブルな金属材料に絶縁被覆したフィルム基板を用いたものも開発されている。このフレキシブル性を生かし、ロールツーロール方式やステッピングロール方式の製造方法により大量生産が可能となった。
【０００６】
上記の薄膜太陽電池は、電気絶縁性フィルム基板上に第１電極（以下、下電極ともいう）、薄膜半導体層からなる光電変換層および第２電極（以下、透明電極ともいう）が積層されてなる光電変換素子（またはセル）が複数形成されている。ある光電変換素子の第１電極と隣接する光電変換素子の第２電極を電気的に接続することを繰り返すことにより、最初の光電変換素子の第１電極と最後の光電変換素子の第２電極とに必要な電圧を出力させることができる。例えば、インバータにより交流化し商用電力源として交流１００Ｖを得るためには、薄膜太陽電池の出力電圧は１００Ｖ以上が望ましく、実際には数１０個以上の素子が直列接続される。
【０００７】
このような光電変換素子とその直列接続は、電極層と光電変換層の成膜と各層のパターニングおよびそれらの組み合わせ手順により形成される。上記太陽電池の構成および製造方法の一例として、本願出願人により、いわゆるＳＣＡＦ（Series Connection through Apertures on Film ）型の薄膜太陽電池が提案されており、例えば特開平１０−２３３５１７号公報や特願平１１−１９３０６号に記載されている。
【０００８】
図２は、上記特開平１０−２３３５１７号公報に記載された薄膜太陽電池の一例を示し、（ａ）は平面図、（ｂ）は（ａ）における線ＡＢＣＤおよびＢＱＣに沿っての断面図であり、（ｃ）は（ａ）におけるＥＥ断面図を示す。
【０００９】
電気絶縁性でフレキシブルな樹脂からなる長尺のフィルム基板上に、順次、第１電極層、光電変換層、第２電極層が積層され、フィルム基板の反対側（裏面）には第３電極層、第４電極層が積層され、裏面電極が形成されている。光電変換層は例えばアモルファスシリコンのpin接合である。フィルム基板用材料としては、ポリイミドのフィルム、例えば厚さ５０μｍのフィルムが用いられている。
【００１０】
フィルムの材質としては、他に、ポリエチレンナフタレート（PEN）、ポリエーテルサルフォン（PES）、ポリエチレンテレフタレート（PET）、またはアラミド系のフィルムなどを用いることができる。
【００１１】
次に、製造工程の概要につき以下に説明する。
【００１２】
先ず、フィルム基板にパンチを用いて、接続孔ｈ１を開け、基板の片側（表側とする）に第１電極層として、スパッタにより銀を、例えば１００ｎｍの厚さに成膜し、これと反対の面（裏側とする）には、第３電極層として、同じく銀電極を成膜する。接続孔ｈ１の内壁で第１電極層と第３電極層とは重なり、導通する。
【００１３】
電極層としては、銀（Ag）以外に、Al，Cu，Ti等の金属をスパッタまたは電子ビーム蒸着等により成膜しても良く、金属酸化膜と金属の多層膜を電極層としても良い。成膜後、表側では、第１電極層を所定の形状にレーザ加工して、下電極ｌ１〜ｌ６をパターニングする。下電極ｌ１〜ｌ６の隣接部は一本の分離線ｇ２を、二列の直列接続の光電変換素子間および周縁導電部ｆとの分離のためには二本の分離線ｇ２を形成し、下電極ｌ１〜ｌ６は分離線により囲まれるようにする。再度パンチを用いて、集電孔ｈ２を開けた後、表側に、光電変換層ｐとしてa-Si層をプラズマＣＶＤにより成膜する。マスクを用いて幅Ｗ２の成膜とし、レーザ加工により二列素子の間だけに第１電極層と同じ分離線を形成する。なお、前記幅Ｗ２は、接続孔ｈ１にまたがってもよい。
【００１４】
さらに第２電極層として表側に透明電極層（ＩＴＯ層）を成膜する。但し、二つの素子列の間とこれに平行な基板の両側端部にはマスクを掛け接続孔ｈ１には成膜しないようにし、素子部のみに成膜する。透明電極層としては、ITO（インシ゛ウムスス゛オキサイト゛）以外に、SnO₂、ZnOなどの酸化物導電層を用いることができる。
【００１５】
次いで裏面全面に第４電極層として金属膜などの低抵抗導電膜からなる層を成膜する。第４電極の成膜により、集電孔ｈ２の内壁で第２電極と第４電極とが重なり、導通する。表側では、レーザ加工により下電極と同じパターンの分離線を入れ、個別の第２電極ｕ１〜ｕ６を形成し、裏側では第３電極と第４電極とを同時にレーザ加工し、接続電極ｅ１２〜ｅ５６、および電力取り出し電極ｏ１，ｏ２を個別化し、基板の周縁部では表側の分離線ｇ３と重なるように分離線ｇ２を形成し、隣接電極間には一本の分離線を形成する。
【００１６】
全ての薄膜太陽電池素子を一括して囲う周縁、および二列の直列接続太陽電池素子の隣接する境界には（周縁導電部ｆの内側）分離線ｇ３がある。分離線ｇ３の中にはどの層も無い。裏側では、全ての電極を一括して囲う周縁、および二列の直列接続電極の隣接する境界には（周縁導電部ｆの内側）分離線ｇ２がある。分離線ｇ２の中にはどの層も無い。
【００１７】
こうして、電力取り出し電極ｏ１−集電孔ｈ２−上電極ｕ１、光電変換層、下電極ｌ１−接続孔ｈ１−接続電極ｅ１２−上電極ｕ２、光電変換層、下電極ｌ２−接続電極ｅ２３−・・・−上電極ｕ６、光電変換層、下電極ｌ６−接続孔ｈ１−電力取出し電極ｏ２の順の光電変換素子の直列接続が完成する。
【００１８】
なお、第３電極層と第４電極層は電気的には同一の電位であるので、以下の説明においては説明の便宜上、併せて一層の接続電極層として扱うこともある。
【００１９】
図３は、構造の理解の容易化のために、薄膜太陽電池の構成を簡略化して斜視図で示したものである。図３において、基板６１の表面に形成した単位光電変換素子６２および基板６１の裏面に形成した接続電極層６３は、それぞれ複数の単位ユニットに完全に分離され、それぞれの分離位置をずらして形成されている。このため、素子６２のアモルファス半導体部分である光電変換層６５で発生した電流は、まず透明電極層６６に集められ、次に該透明電極層領域に形成された集電孔６７（ｈ２）を介して背面の接続電極層６３に通じ、さらに該接続電極層領域で素子の透明電極層領域の外側に形成された直列接続用の接続孔６８（ｈ１）を介して上記素子と隣り合う素子の透明電極層領域の外側に延びている下電極層６４に達し、両素子の直列接続が行われている。
【００２０】
上記薄膜太陽電池の簡略化した製造工程を図４（a）から（g）に示す。プラスチックフィルム７１を基板として（工程（a））、これに接続孔７８を形成し（工程（b））、基板の両面に第１電極層（下電極）７４および第３電極層（接続電極の一部）７３を形成（工程（c））した後、接続孔７８と所定の距離離れた位置に集電孔７７を形成する（工程（d））。工程（c）と工程（d）との間に、第１電極層（下電極）７４を所定の形状にレーザ加工して、下電極をパターニングする工程があるが、ここではこの工程の図を省略している。
【００２１】
次に、第１電極層７４の上に、光電変換層となる半導体層７５および第２電極層である透明電極層７６を順次形成するとともに（工程（e）および工程（f））、第３電極層７３の上に第４電極層（接続電極層）７９を形成する（工程（g））。この後、レーザビームを用いて、基板７１の両側の薄膜を分離加工して図３に示すような直列接続構造を形成する。
【００２２】
なお、図４においては、集電孔ｈ２内における透明電極層７６と第４電極層７９との接続をそれぞれの層を重ねて２層で図示しているが、前記図２においては、電気的に一層として扱い、１層で図示している。
【００２３】
【発明が解決しようとする課題】
ところで、上記ＳＣＡＦ構造の薄膜太陽電池の製造方法においては、下記のような問題があった。
【００２４】
前述のように、レーザビームを用いて薄膜のパターニング分離加工を行う際、レーザビームが基板を透過して加工面の反対側に形成している金属電極をも加工するため、薄膜電極の剥がれが生じることがあり、品質の安定性を十分に確保できない問題があった。
【００２５】
この発明は、上記のような問題点を解消するためになされたもので、この発明の課題は、パターニング分離加工の際の薄膜の損傷を防止して信頼性の向上を図った薄膜太陽電池の製造方法およびこの方法を実施するための製造装置を提供することにある。
【００２６】
【課題を解決するための手段】
前述の課題を解決するため、請求項１の発明によれば、電気絶縁性を有する基板の表面に下電極層としての第１電極層，光電変換層，透明電極層（第２電極層）を順次積層してなる光電変換部と、前記基板の裏面に形成した接続電極層としての第３電極層および第４電極層とを備え、前記光電変換部および接続電極層を互いに位置をずらして単位部分にパターニングしてなり、前記光電変換層形成領域内に形成した接続孔ならびに集電孔を介して、前記表面上の互いにパターニングされて隣合う単位光電変換部分（ユニットセル）を電気的に直列に接続してなる薄膜太陽電池の製造方法であって、以下の１）から６）までの全工程、即ち、
１）基板に接続孔を開け、基板表面に第１電極層を形成し、裏面に第３電極層を形成する工程。
２）前記基板に集電孔を開ける工程。
３）第１電極層ならびに接続孔および集電孔内面上に、光電変換層を形成する工程。
４）接続孔形成領域を除く光電変換層の上ならびに集電孔内面の光電変換層上に、透明電極層を形成する工程。
５）第３電極層の上ならびに接続孔内面の光電変換層上および集電孔内面の透明電極層上に、第４電極層を形成する工程。
６）基板表面の光電変換部と基板裏面の接続電極層とを、化学的エッチング装置により、一括してパターニング加工（以下、化学的エッチング加工という。）する工程。
を含み、さらに、前記化学的エッチング加工前に、非加工部分を熱剥離フィルムによりマスクし、化学的エッチング加工後に、所定温度で加熱して熱剥離フィルムを除去することを特徴とする。
上記製造方法によれば、基板表面と裏面を略同時に一括して化学的エッチング装置によりパターニング加工できるので、薄膜電極が熱影響によって剥がれることはなく、信頼性の向上と工程の簡略化を図ることができる。
【００２７】
上記熱剥離フィルムのマスクの使用により、パターニング加工が容易になるとともに、マスクの除去も容易となる。ところで、マスクとして感光性の肉厚なレジストを用いて、半導体層をエッチングすることは、公知である（例えば、特開昭５９−１６１８８３号公報参照）。この場合、露光後に半導体層に残されたレジストは、エッチングの際の半導体保護層として機能し、またレジストを剥離する場合には化学薬品を用いている。
【００２８】
これに対して、請求項１の発明におけるマスクは、非加工部分にのみマスクする予めパターン化されたマスクであって、また、加熱により容易に剥離可能なマスクであるため、レジストに比べて、作業が容易となる。
【００２９】
さらに、量産性向上の観点から、請求項２の発明が好適である。
【００３０】
即ち、電気絶縁性を有する基板の表面に下電極層としての第１電極層，光電変換層，透明電極層（第２電極層）を順次積層してなる光電変換部と、前記基板の裏面に形成した接続電極層としての第３電極層および第４電極層とを備え、前記光電変換部および接続電極層を互いに位置をずらして単位部分にパターニングしてなり、前記光電変換層形成領域内に形成した接続孔ならびに集電孔を介して、前記表面上の互いにパターニングされて隣合う単位光電変換部分（ユニットセル）を電気的に直列に接続してなる薄膜太陽電池の製造方法であって、以下の１）から６）までの全工程、即ち、
１）基板に接続孔を開け、基板表面に第１電極層を形成し、裏面に第３電極層を形成する工程。
２）前記基板に集電孔を開ける工程。
３）第１電極層ならびに接続孔および集電孔内面上に、光電変換層を形成する工程。
４）接続孔形成領域を除く光電変換層の上ならびに集電孔内面の光電変換層上に、透明電極層を形成する工程。
５）第３電極層の上ならびに接続孔内面の光電変換層上および集電孔内面の透明電極層上に、第４電極層を形成する工程。
６）基板表面の光電変換部と基板裏面の接続電極層とを、化学的エッチング加工する工程。
を含み、さらに、前記１）〜５）の工程終了後の基板を、巻き出しロールから巻き出し、この基板の両面にそれぞれ所定のパターンを予め形成した熱剥離フィルムを貼り合わせ、この貼り合わせた基板に化学的エッチング加工を施し、続いて水洗浄を行った後、所定温度で加熱して熱剥離フィルムを除去し、このパターニングされた基板を、巻取りロールに巻き取ることとする。
【００３１】
さらにまた、複数の薄膜の化学的エッチング加工を、確実かつ効率的に行なう観点から、請求項３の発明が好ましい。即ち、請求項１または２に記載の薄膜太陽電池の製造方法であって、前記化学的エッチング加工に際し、透明電極層と、光電変換層、ならびに、第１電極層および接続電極層の加工は、それぞれ異なるエッチング液を用いて行なう。
【００３２】
また、前記製造方法を実施するための量産化装置としては、請求項４の発明が好適である。即ち、電気絶縁性を有する基板の表面に下電極層としての第１電極層，光電変換層，透明電極層（第２電極層）を順次積層してなる光電変換部と、前記基板の裏面に形成した接続電極層としての第３電極層および第４電極層とを備え、前記光電変換部および接続電極層を互いに位置をずらして単位部分にパターニングしてなり、前記光電変換層形成領域内に形成した接続孔ならびに集電孔を介して、前記表面上の互いにパターニングされて隣合う単位光電変換部分（ユニットセル）を電気的に直列に接続してなる薄膜太陽電池の製造装置において、
前記光電変換部および接続電極層を形成した基板の両面にそれぞれ所定のパターンを予め形成した熱剥離フィルムを貼り合わせるロールラミネータと、複数のエッチング槽と洗浄槽とを有する化学エッチング装置と、熱剥離フィルムを所定温度で加熱して基板から除去する加熱除去装置と、基板のロール搬送装置とを備えるものとする。
【００３３】
【発明の実施の形態】
図面に基づき、本発明の実施例について以下に述べる。
【００３４】
図１は、請求項４の発明に関わる薄膜太陽電池の製造装置の実施例を示す概略構成図である。請求項１の発明における製造工程１）〜５）は、図４に示す手順と同等である。まず、図４を引用して、製造工程１）〜５）の実施例を述べ、製造工程６）の化学的エッチング工程の詳細については、図１を引用して述べる。
【００３５】
図４において、基板７１としては、膜厚３０〜５０μｍのポリイミドフィルムを用いた。プラスチックフィルム基板としては、アラミド、ＰＥＮ，ＰＥＳ，ＰＥＴなどを用いてもよい。コアに巻かれたプラスチック基板７１には、ロールツーロール方式パンチ装置により複数の直径０．５〜２ｍｍの直列接続用の接続孔７８を形成する。
【００３６】
次に、このプラスチック基板をロールツーロール方式電極形成装置に装着し、一面に第１電極層７４およびその反対面に第３電極層７３を数百ｎｍ厚さで形成する。電極材料にはＡｌを用いたが、Ａｇなどの金属材料、ＩＴＯ，ＺｎＯなどの透明導電膜、およびその複合膜などを用いてもよい。
【００３７】
次に、ロールツーロール方式パンチ装置により、接続孔７８と、所定の距離離れた位置に直径０．５〜２ｍｍの集電孔７７を形成する。上記のように、接続孔７８、第１電極層７４および第３電極層７３、集電孔７７が形成されたプラスチック基板をステッピングロール方式薄膜形成装置に装着し、第１電極層７４の上に、アモルファスシリコンからなる半導体の光電変換層７５、ＩＴＯからなる透明電極層７６を順次積層して光電変換部（図３の６２に相当する部分）を形成する。なお、透明電極層７６の形成の際には、接続孔７８およびその近傍には膜が形成されないようにした。
【００３８】
さらに、ステッピングロール方式薄膜形成装置内にて、光電変換層７５、透明電極層７６を順次積層した面とは反対の面に、第４電極層７９を最終的に形成した。次に、後述する図１のロール方式の化学エッチング装置により、所定のパターンで光電変換部（図３の６２に相当する部分）およびその反対面の接続電極層（図３の６３）の分離加工を行う。このとき、光電変換部を分離する位置と接続電極層を分離する位置をずらすことにより、集電孔および接続孔を介して一面上で互いに絶縁分離されている単位太陽電池が直列に接続される。
【００３９】
次に、エッチング工程の詳細について、図１により説明する。図１の薄膜太陽電池の製造装置は、光電変換部および接続電極層を形成した基板フィルム３１の両面にそれぞれ所定のパターンを予め形成した熱剥離フィルム３２，３３を貼り合わせるロールラミネータ２４と、複数のエッチング槽８１〜８３と洗浄槽９１〜９３とを有する化学エッチング装置５０と、熱剥離フィルムを所定温度で加熱して基板から除去する加熱除去装置４０と、基板のロール搬送装置としての巻き出しロール２１および巻取りロール４１とを備える。
【００４０】
上記装置において、薄膜が形成された基板フィルム３１が、巻き出しロール２１から巻き出され、この基板フィルム３１の上面側から光電変換部のパターンを予め有する熱剥離フィルム３２、下面側から接続電極層のパターンを有する熱剥離フィルム３３をそれぞれロール２２および２３から巻き出し、ロールラミネータ２４のプレスロールで３種のフィルムを貼り合わせ、これを化学エッチング装置５０に送る。熱剥離フィルム３２、３３としては、日東電工製の商品名「リバアルファ」を用いた。
【００４１】
前記「リバアルファ」はシート状の粘着フィルムであるが、このフィルムは、ＰＥＴフィルムに対しては９０℃以上で接着強度が０となるとともに、温度１００℃では１秒以内で接着強度が０になるという特性を有する熱剥離フィルムである。
【００４２】
熱剥離フィルム３２、３３をフィルム基板３１にマスクして、化学エッチング装置５０における第１のエッチング槽８１では、塩化鉄と硝酸の水溶液により透明電極層（ＩＴＯ層）を除去し、第１の水洗槽９１でエッチング液を落とした後、第２のエッチング槽８２において、フツ酸、硝酸と酢酸の混合液により、光電変換層としてのアモルファスシリコン層を除去し、第２水洗槽９２を経て、第３のエッチング槽８３において、りん酸、硝酸、酢酸の水溶液により、第１電極層および背面側の接続電極層であるＡｌを同時に除去する。
【００４３】
水洗槽９３を経た後、加熱除去装置４０において、フィルム基板の上下より８０℃〜１００℃に加熱を行って、マスクとして用いた熱剥離フィルムを基板フィルムから剥離し、これをそれぞれ用意した巻取りロール４２および４３ならびに基板の巻取りロール４１に巻き取る。なお、薄膜のエッチング速度は１００ｎｍ／分〜３００ｎｍ／分の範囲とした。
【００４４】
薄膜の分離加工を終了した基板フィルムは、特性測定、選別、モジュール化などの太陽電池モジュール製造工程における次工程へと進め、太陽電池としての所期の性能が得られることを確認した。
【００４５】
【発明の効果】
この発明によれば前述のように、電気絶縁性を有する基板の表面に下電極層としての第１電極層，光電変換層，透明電極層（第２電極層）を順次積層してなる光電変換部と、前記基板の裏面に形成した接続電極層としての第３電極層および第４電極層とを備え、前記光電変換部および接続電極層を互いに位置をずらして単位部分にパターニングしてなり、前記光電変換層形成領域内に形成した接続孔ならびに集電孔を介して、前記表面上の互いにパターニングされて隣合う単位光電変換部分（ユニットセル）を電気的に直列に接続してなる薄膜太陽電池の製造方法であって、
１）基板に接続孔を開け、基板表面に第１電極層を形成し、裏面に第３電極層を形成する工程。
２）前記基板に集電孔を開ける工程。
３）第１電極層ならびに接続孔および集電孔内面上に、光電変換層を形成する工程。
４）接続孔形成領域を除く光電変換層の上ならびに集電孔内面の光電変換層上に、透明電極層を形成する工程。
５）第３電極層の上ならびに接続孔内面の光電変換層上および集電孔内面の透明電極層上に、第４電極層を形成する工程。
６）基板表面の光電変換部と基板裏面の接続電極層とを、化学的エッチング装置により、一括してパターニング加工（化学的エッチング加工）する工程。
を含み、
さらに、前記化学的エッチング加工前に、非加工部分を熱剥離フィルムによりマスクし、化学的エッチング加工後に、所定温度で加熱して熱剥離フィルムを除去するか、もしくは、前記１）〜５）の工程終了後の基板を、巻き出しロールから巻き出し、この基板の両面にそれぞれ所定のパターンを予め形成した熱剥離フィルムを貼り合わせ、この貼り合わせた基板に化学的エッチング加工を施し、続いて水洗浄を行った後、所定温度で加熱して熱剥離フィルムを除去し、このパターニングされた基板を、巻取りロールに巻き取ることにより、
また、上記製造方法を実施するための装置として、前記光電変換部および接続電極層を形成した基板の両面にそれぞれ所定のパターンを予め形成した熱剥離フィルムを貼り合わせるロールラミネータと、複数のエッチング槽と洗浄槽とを有する化学エッチング装置と、熱剥離フィルムを所定温度で加熱して基板から除去する加熱除去装置と、基板のロール搬送装置とを備えるものとすることにより、パターニング分離加工の際の薄膜の損傷を防止して信頼性の向上を図り、製造プロセスのスループットの向上を図ることができる。
【図面の簡単な説明】
【図１】この発明の実施例に関わる薄膜太陽電池の製造装置の概略構成図
【図２】ＳＣＡＦ型薄膜太陽電池の構成図
【図３】ＳＣＡＦ型薄膜太陽電池の概略構成を示す斜視図
【図４】ＳＣＡＦ型薄膜太陽電池の製造工程の概略を示す図
【符号の説明】
２１：基板の巻き出しロール、２４：ロールラミネータ、３１：フィルム基板、３２，３３：熱剥離フィルム、４０：加熱除去装置、４１：基板の巻取りロール、５０：化学エッチング装置、６１，７１：基板、６２：単位光電変換素子、６３：接続電極層、６４，７４：第１電極層（下電極層）、６５，７５：光電変換層、６６，７６：第２電極層（透明電極層）、６７，７７：集電孔、６８，７８：接続孔、７３：第３電極層、７９：第４電極層、８１〜８３：エッチング槽、９１〜９３：洗浄槽。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing a thin film solar cell in which a plurality of unit cells are connected in series.
[0002]
[Prior art]
Currently, clean energy research and development is underway from the standpoint of environmental protection. Among them, solar cells are attracting attention because their resources (sunlight) are infinite and pollution-free.
[0003]
A typical example of a solar cell (photoelectric conversion device) in which a plurality of solar cell elements formed on the same substrate are connected in series is a thin film solar cell.
[0004]
Thin-film solar cells are expected to become the mainstream of solar cells in the future because they are thin and lightweight, inexpensive to manufacture, and easy to increase in area, and are attached to roofs and windows of buildings in addition to power supply. Demand is also expanding for commercial and general residential use.
[0005]
Conventional thin film solar cells generally use a glass substrate. In recent years, research and development of flexible solar cells using plastic films has been promoted and put into practical use in terms of weight reduction, workability, and mass productivity. Furthermore, the thing using the film substrate which carried out the insulation coating to the flexible metal material is also developed. Taking advantage of this flexibility, mass production became possible by a roll-to-roll method or a stepping roll method.
[0006]
In the above thin film solar cell, a first electrode (hereinafter also referred to as a lower electrode), a photoelectric conversion layer composed of a thin film semiconductor layer, and a second electrode (hereinafter also referred to as a transparent electrode) are laminated on an electrically insulating film substrate. A plurality of photoelectric conversion elements (or cells) are formed. By repeating electrically connecting the first electrode of a certain photoelectric conversion element and the second electrode of the adjacent photoelectric conversion element, the first electrode of the first photoelectric conversion element and the second electrode of the last photoelectric conversion element Can output the voltage required for For example, in order to obtain an alternating current of 100 V as a commercial power source by alternating current with an inverter, the output voltage of the thin-film solar cell is desirably 100 V or higher, and actually several tens or more elements are connected in series.
[0007]
Such a photoelectric conversion element and its series connection are formed by forming an electrode layer and a photoelectric conversion layer, patterning each layer, and a combination procedure thereof. As an example of the configuration and manufacturing method of the above solar cell, the applicant of the present application has proposed a so-called SCAF (Series Connection through Apertures on Film) type thin film solar cell. For example, Japanese Patent Application Laid-Open No. 10-233517 and Japanese Patent Application No. 11-19306.
[0008]
FIG. 2 shows an example of the thin film solar cell described in the above-mentioned JP-A-10-233517, wherein (a) is a plan view and (b) is a cross-sectional view taken along lines ABCD and BQC in (a). Yes, (c) shows an EE cross-sectional view in (a).
[0009]
A first electrode layer, a photoelectric conversion layer, and a second electrode layer are sequentially laminated on a long film substrate made of an electrically insulating and flexible resin, and a third electrode layer is formed on the opposite side (back surface) of the film substrate. The fourth electrode layer is laminated to form a back electrode. The photoelectric conversion layer is, for example, an amorphous silicon pin junction. As the film substrate material, a polyimide film, for example, a film having a thickness of 50 μm is used.
[0010]
As the material for the film, polyethylene naphthalate (PEN), polyethersulfone (PES), polyethylene terephthalate (PET), or an aramid film can be used.
[0011]
Next, the outline of the manufacturing process will be described below.
[0012]
First, using a punch in the film substrate, a connection hole h1 is opened, and silver is formed to a thickness of, for example, 100 nm by sputtering as a first electrode layer on one side (front side) of the substrate. Similarly, a silver electrode is formed on the surface (the back side) as the third electrode layer. The first electrode layer and the third electrode layer overlap with each other on the inner wall of the connection hole h1, and are electrically connected.
[0013]
As the electrode layer, in addition to silver (Ag), a metal such as Al, Cu, or Ti may be formed by sputtering or electron beam evaporation, or a metal oxide film and a metal multilayer film may be used as the electrode layer. After the film formation, on the front side, the first electrode layer is laser processed into a predetermined shape, and the lower electrodes 11 to 16 are patterned. Adjacent portions of the lower electrodes l1 to l6 form one separation line g2, and two separation lines g2 are formed for separation between the two series-connected photoelectric conversion elements and the peripheral conductive portion f. The electrodes l1 to l6 are surrounded by a separation line. After using the punch again to open the current collecting hole h2, an a-Si layer as a photoelectric conversion layer p is formed on the front side by plasma CVD. A film having a width W2 is formed using a mask, and the same separation line as that of the first electrode layer is formed only between the two-row elements by laser processing. The width W2 may extend over the connection hole h1.
[0014]
Further, a transparent electrode layer (ITO layer) is formed on the front side as the second electrode layer. However, a mask is applied between the two element rows and on both side edges of the substrate parallel to the element row so as not to form the film in the connection hole h1, and the film is formed only on the element part. As the transparent electrode layer, an oxide conductive layer such as SnO ₂ or ZnO can be used in addition to ITO (Indium Sulfoxide).
[0015]
Next, a layer made of a low-resistance conductive film such as a metal film is formed as a fourth electrode layer on the entire back surface. By forming the fourth electrode, the second electrode and the fourth electrode overlap with each other on the inner wall of the current collecting hole h2, and are brought into conduction. On the front side, separation lines having the same pattern as the lower electrode are formed by laser processing to form individual second electrodes u1 to u6, and on the back side, the third electrode and the fourth electrode are simultaneously laser processed to provide connection electrodes e12 to e56. In addition, the power extraction electrodes o1 and o2 are individualized, the separation line g2 is formed so as to overlap the front-side separation line g3 at the periphery of the substrate, and a single separation line is formed between the adjacent electrodes.
[0016]
There is a separation line g3 at the periphery that encloses all the thin-film solar cell elements in a lump and the adjacent boundary between the two rows of series-connected solar cell elements (inside the peripheral conductive part f). There are no layers in the separation line g3. On the back side, there is a separation line g2 (inside the peripheral conductive portion f) at the peripheral edge that encloses all the electrodes together and at the adjacent boundary of the two rows of series connection electrodes. There are no layers in the separation line g2.
[0017]
In this way, power extraction electrode o1-collection hole h2-upper electrode u1, photoelectric conversion layer, lower electrode l1-connection hole h1-connection electrode e12-upper electrode u2, photoelectric conversion layer, lower electrode l2-connection electrode e23- -The series connection of the photoelectric conversion elements in the order of the upper electrode u6, the photoelectric conversion layer, the lower electrode l6-the connection hole h1-the power extraction electrode o2 is completed.
[0018]
Since the third electrode layer and the fourth electrode layer are electrically at the same potential, in the following description, for convenience of explanation, they may be treated as a single connection electrode layer.
[0019]
FIG. 3 is a perspective view showing a simplified configuration of a thin film solar cell for easy understanding of the structure. In FIG. 3, the unit photoelectric conversion element 62 formed on the front surface of the substrate 61 and the connection electrode layer 63 formed on the back surface of the substrate 61 are completely separated into a plurality of unit units, and are formed by shifting the separation positions. ing. For this reason, the current generated in the photoelectric conversion layer 65 which is an amorphous semiconductor portion of the element 62 is first collected in the transparent electrode layer 66 and then through the current collecting hole 67 (h2) formed in the transparent electrode layer region. And transparent to the element adjacent to the element through a connection hole 68 (h1) for series connection formed in the connection electrode layer 63 and outside the transparent electrode layer area of the element. The lower electrode layer 64 extending to the outside of the electrode layer region is reached, and both elements are connected in series.
[0020]
The simplified manufacturing process of the thin film solar cell is shown in FIGS. Using the plastic film 71 as a substrate (step (a)), a connection hole 78 is formed in this (step (b)), and a first electrode layer (lower electrode) 74 and a third electrode layer (connection electrode) are formed on both sides of the substrate. After (part) 73 is formed (step (c)), a current collecting hole 77 is formed at a position away from the connection hole 78 by a predetermined distance (step (d)). There is a step of patterning the lower electrode by laser processing the first electrode layer (lower electrode) 74 into a predetermined shape between the step (c) and the step (d). Omitted.
[0021]
Next, the semiconductor layer 75 to be a photoelectric conversion layer and the transparent electrode layer 76 to be the second electrode layer are sequentially formed on the first electrode layer 74 (step (e) and step (f)), and the third A fourth electrode layer (connection electrode layer) 79 is formed on the electrode layer 73 (step (g)). Thereafter, the thin film on both sides of the substrate 71 is separated using a laser beam to form a series connection structure as shown in FIG.
[0022]
In FIG. 4, the connection between the transparent electrode layer 76 and the fourth electrode layer 79 in the current collecting hole h2 is shown by two layers, but in FIG. Are shown as one layer.
[0023]
[Problems to be solved by the invention]
By the way, in the manufacturing method of the said thin film solar cell of a SCAF structure, there existed the following problems.
[0024]
As described above, when performing patterning separation processing of a thin film using a laser beam, the laser beam passes through the substrate and also processes the metal electrode formed on the opposite side of the processing surface. There was a problem that quality stability could not be secured sufficiently.
[0025]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a thin film solar cell that is improved in reliability by preventing damage to the thin film during patterning separation processing. The object is to provide a manufacturing method and a manufacturing apparatus for carrying out the method.
[0026]
[Means for Solving the Problems]
In order to solve the above-described problems, according to the invention of claim 1, the first electrode layer, the photoelectric conversion layer, and the transparent electrode layer (second electrode layer) as the lower electrode layer are provided on the surface of the substrate having electrical insulation. A photoelectric conversion unit formed by sequentially stacking, and a third electrode layer and a fourth electrode layer as connection electrode layers formed on the back surface of the substrate, wherein the photoelectric conversion unit and the connection electrode layer are displaced from each other The unit photoelectric conversion parts (unit cells) adjacent to each other patterned on the surface are electrically connected in series via the connection hole and the current collecting hole formed in the photoelectric conversion layer forming region. All steps of the method for manufacturing a thin-film solar cell formed by connecting, from 6) to below 1), i.e.,
1) A step of forming a connection hole in the substrate, forming a first electrode layer on the substrate surface, and forming a third electrode layer on the back surface.
2) A step of opening current collecting holes in the substrate.
3) The process of forming a photoelectric converting layer on a 1st electrode layer, a connection hole, and a current collection hole inner surface.
4) A step of forming a transparent electrode layer on the photoelectric conversion layer excluding the connection hole forming region and on the photoelectric conversion layer on the inner surface of the current collecting hole.
5) A step of forming a fourth electrode layer on the third electrode layer, on the photoelectric conversion layer on the inner surface of the connection hole, and on the transparent electrode layer on the inner surface of the current collecting hole.
6) A step of patterning the photoelectric conversion part on the substrate surface and the connection electrode layer on the back surface of the substrate in a batch with a chemical etching apparatus (hereinafter referred to as chemical etching process) .
Furthermore, before the chemical etching process, the non-processed portion is masked with a heat release film, and after the chemical etching process, the heat release film is removed by heating at a predetermined temperature.
According to the above manufacturing method, the front surface and the back surface of the substrate can be patterned almost simultaneously by a chemical etching apparatus, so that the thin film electrode is not peeled off due to thermal influence, and the reliability is improved and the process is simplified. Can do.
[0027]
The use of the mask of the thermal release film facilitates patterning and facilitates removal of the mask. Incidentally, it is known to etch a semiconductor layer using a photosensitive thick resist as a mask (see, for example, Japanese Patent Laid-Open No. 59-161883). In this case, the resist left in the semiconductor layer after the exposure functions as a semiconductor protective layer at the time of etching, and chemicals are used when the resist is peeled off.
[0028]
On the other hand, the mask according to the first aspect of the present invention is a pre-patterned mask that masks only non-processed portions, and is a mask that can be easily peeled off by heating. Work becomes easy.
[0029]
Furthermore, the invention of claim 2 is preferable from the viewpoint of improving mass productivity .
[0030]
That is, a photoelectric conversion part formed by sequentially laminating a first electrode layer as a lower electrode layer, a photoelectric conversion layer, and a transparent electrode layer (second electrode layer) on the surface of an electrically insulating substrate, and a back surface of the substrate A third electrode layer and a fourth electrode layer as the formed connection electrode layers, wherein the photoelectric conversion part and the connection electrode layer are patterned into unit parts while being shifted from each other, and within the photoelectric conversion layer formation region A method of manufacturing a thin film solar cell in which unit photoelectric conversion portions (unit cells) that are patterned and adjacent to each other on the surface are electrically connected in series through the formed connection hole and the current collection hole, All the following steps 1) to 6):
1) A step of forming a connection hole in the substrate, forming a first electrode layer on the substrate surface, and forming a third electrode layer on the back surface.
2) A step of opening current collecting holes in the substrate.
3) The process of forming a photoelectric converting layer on a 1st electrode layer, a connection hole, and a current collection hole inner surface.
4) A step of forming a transparent electrode layer on the photoelectric conversion layer excluding the connection hole forming region and on the photoelectric conversion layer on the inner surface of the current collecting hole.
5) A step of forming a fourth electrode layer on the third electrode layer, on the photoelectric conversion layer on the inner surface of the connection hole, and on the transparent electrode layer on the inner surface of the current collecting hole.
6) A step of chemically etching the photoelectric conversion portion on the substrate surface and the connection electrode layer on the back surface of the substrate.
Furthermore, the substrate after completion of the steps 1) to 5) is unwound from an unwinding roll, and a heat release film in which a predetermined pattern is formed in advance on each side of the substrate is bonded to the substrate. The substrate is subjected to a chemical etching process, followed by washing with water, followed by heating at a predetermined temperature to remove the heat-release film, and the patterned substrate is taken up on a take-up roll.
[0031]
Furthermore, the invention of claim 3 is preferable from the viewpoint of reliably and efficiently performing chemical etching of a plurality of thin films. That is, in the method for manufacturing a thin film solar cell according to claim 1 or 2 , in the chemical etching process, the transparent electrode layer, the photoelectric conversion layer, and the first electrode layer and the connection electrode layer are processed, Each is performed using a different etching solution.
[0032]
In addition, as a mass production apparatus for carrying out the manufacturing method, the invention of claim 4 is suitable. That is, a photoelectric conversion part formed by sequentially laminating a first electrode layer as a lower electrode layer, a photoelectric conversion layer, and a transparent electrode layer (second electrode layer) on the surface of an electrically insulating substrate, and a back surface of the substrate A third electrode layer and a fourth electrode layer as the formed connection electrode layers, wherein the photoelectric conversion portion and the connection electrode layer are patterned into unit portions while being shifted from each other, and within the photoelectric conversion layer formation region In the thin-film solar cell manufacturing apparatus in which unit photoelectric conversion parts (unit cells) that are patterned and adjacent to each other on the surface are electrically connected in series through the formed connection hole and the current collection hole,
A roll laminator for bonding a thermal peeling film having a predetermined pattern formed on both sides of the substrate on which the photoelectric conversion part and the connection electrode layer are formed, a chemical etching apparatus having a plurality of etching tanks and a cleaning tank, and thermal peeling A heating / removing device that heats the film at a predetermined temperature and removes it from the substrate, and a substrate roll conveying device are provided.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0034]
FIG. 1 is a schematic configuration diagram showing an embodiment of a thin-film solar cell manufacturing apparatus according to the invention of claim 4 . The manufacturing steps 1) to 5) in the invention of claim 1 are equivalent to the procedure shown in FIG. First, referring to FIG. 4, examples of the manufacturing steps 1) to 5) will be described, and details of the chemical etching step of the manufacturing step 6) will be described with reference to FIG. 1.
[0035]
In FIG. 4, as the substrate 71, a polyimide film having a film thickness of 30 to 50 μm was used. As the plastic film substrate, aramid, PEN, PES, PET, or the like may be used. A plurality of connection holes 78 for series connection having a diameter of 0.5 to 2 mm are formed in the plastic substrate 71 wound around the core by a roll-to-roll punching device.
[0036]
Next, this plastic substrate is mounted on a roll-to-roll type electrode forming apparatus, and a first electrode layer 74 is formed on one surface and a third electrode layer 73 is formed on the opposite surface with a thickness of several hundred nm. Al is used as the electrode material, but a metal material such as Ag, a transparent conductive film such as ITO and ZnO, and a composite film thereof may be used.
[0037]
Next, a current collecting hole 77 having a diameter of 0.5 to 2 mm is formed at a position away from the connection hole 78 by a roll-to-roll punch device. As described above, the plastic substrate on which the connection hole 78, the first electrode layer 74 and the third electrode layer 73, and the current collection hole 77 are formed is mounted on the stepping roll type thin film forming apparatus, and the first electrode layer 74 is formed on the plastic substrate. Then, a semiconductor photoelectric conversion layer 75 made of amorphous silicon and a transparent electrode layer 76 made of ITO are sequentially stacked to form a photoelectric conversion portion (portion corresponding to 62 in FIG. 3). Note that when the transparent electrode layer 76 was formed, no film was formed in the connection hole 78 and the vicinity thereof.
[0038]
Furthermore, the 4th electrode layer 79 was finally formed in the surface on the opposite side to the surface which laminated | stacked the photoelectric converting layer 75 and the transparent electrode layer 76 in the stepping roll type thin film forming apparatus. Next, separation processing of the photoelectric conversion portion (the portion corresponding to 62 in FIG. 3) and the connection electrode layer (63 in FIG. 3) on the opposite surface with a predetermined pattern is performed by the roll type chemical etching apparatus of FIG. I do. At this time, the unit solar cells that are insulated from each other on one surface are connected in series via the current collecting holes and the connection holes by shifting the position for separating the photoelectric conversion portion and the position for separating the connection electrode layer. .
[0039]
Next, details of the etching process will be described with reference to FIG. The thin-film solar cell manufacturing apparatus in FIG. 1 includes a roll laminator 24 that bonds heat-peeling films 32 and 33 each having a predetermined pattern formed on both surfaces of a substrate film 31 on which a photoelectric conversion portion and a connection electrode layer are formed. Chemical etching apparatus 50 having etching tanks 81 to 83 and cleaning tanks 91 to 93, heating and removing apparatus 40 that heats and removes the heat-release film from the substrate at a predetermined temperature, and unwinding the substrate as a roll conveying apparatus A roll 21 and a take-up roll 41 are provided.
[0040]
In the above apparatus, a substrate film 31 on which a thin film is formed is unwound from an unwinding roll 21, and a thermal peeling film 32 having a photoelectric conversion part pattern in advance from the upper surface side of the substrate film 31, and a connection electrode layer from the lower surface side. The thermal release film 33 having the pattern is unwound from the rolls 22 and 23, and the three kinds of films are bonded together by the press roll of the roll laminator 24, and sent to the chemical etching apparatus 50. As the heat release films 32 and 33, the product name “Riva Alpha” manufactured by Nitto Denko was used.
[0041]
The “Riva Alpha” is a sheet-like pressure-sensitive adhesive film. This film has an adhesive strength of 0 at 90 ° C. or more and a PET film at 0 ° C. within 1 second at a temperature of 100 ° C. It is a heat release film having the characteristics of
[0042]
In the first etching tank 81 in the chemical etching apparatus 50, the transparent electrode layer (ITO layer) is removed with an aqueous solution of iron chloride and nitric acid, and the first water washing is performed by masking the heat release films 32 and 33 on the film substrate 31. After dropping the etching solution in the tank 91, the amorphous silicon layer as a photoelectric conversion layer is removed with a mixed solution of hydrofluoric acid, nitric acid and acetic acid in the second etching tank 82, and after passing through the second water-washing tank 92, In the etching tank 83, Al, which is the first electrode layer and the connection electrode layer on the back side, is simultaneously removed with an aqueous solution of phosphoric acid, nitric acid, and acetic acid.
[0043]
After passing through the water rinsing tank 93, in the heating and removal apparatus 40, heating is performed from 80 ° C. to 100 ° C. from the upper and lower sides of the film substrate, and the heat release film used as a mask is peeled off from the substrate film, The rolls 42 and 43 and the substrate winding roll 41 are wound up. The etching rate of the thin film was in the range of 100 nm / min to 300 nm / min.
[0044]
The substrate film that finished the thin film separation process was advanced to the next step in the solar cell module manufacturing process such as characteristic measurement, selection, and modularization, and it was confirmed that the expected performance as a solar cell was obtained.
[0045]
【The invention's effect】
According to the present invention, as described above, the photoelectric conversion obtained by sequentially laminating the first electrode layer, the photoelectric conversion layer, and the transparent electrode layer (second electrode layer) as the lower electrode layer on the surface of the electrically insulating substrate. And a third electrode layer and a fourth electrode layer as connection electrode layers formed on the back surface of the substrate, the photoelectric conversion unit and the connection electrode layer are shifted to each other and patterned into unit parts, Thin film solar in which unit photoelectric conversion portions (unit cells) that are patterned and adjacent to each other on the surface are electrically connected in series via connection holes and current collection holes formed in the photoelectric conversion layer formation region A battery manufacturing method comprising:
1) A step of forming a connection hole in the substrate, forming a first electrode layer on the substrate surface, and forming a third electrode layer on the back surface.
2) A step of opening current collecting holes in the substrate.
3) The process of forming a photoelectric converting layer on a 1st electrode layer, a connection hole, and a current collection hole inner surface.
4) A step of forming a transparent electrode layer on the photoelectric conversion layer excluding the connection hole forming region and on the photoelectric conversion layer on the inner surface of the current collecting hole.
5) A step of forming a fourth electrode layer on the third electrode layer, on the photoelectric conversion layer on the inner surface of the connection hole, and on the transparent electrode layer on the inner surface of the current collecting hole.
6) A step of patterning (chemical etching) the photoelectric conversion portion on the substrate surface and the connection electrode layer on the back surface of the substrate in a batch using a chemical etching apparatus.
Only including,
Further, before the chemical etching process, the non-processed part is masked with a heat release film, and after the chemical etching process, the heat release film is removed by heating at a predetermined temperature, or the above 1) to 5) The substrate after the completion of the process is unwound from an unwinding roll, and a thermal release film in which a predetermined pattern is formed in advance is bonded to both surfaces of the substrate, and the bonded substrate is subjected to chemical etching, After performing cleaning, the film is heated at a predetermined temperature to remove the heat-release film, and the patterned substrate is wound on a winding roll ,
Further, as an apparatus for carrying out the above manufacturing method, a roll laminator for bonding a thermal peeling film in which a predetermined pattern is previously formed on both surfaces of the substrate on which the photoelectric conversion portion and the connection electrode layer are formed, and a plurality of etching tanks And a chemical etching apparatus having a cleaning tank, a heat removal apparatus that heats and removes the heat-release film from the substrate at a predetermined temperature, and a roll transport apparatus for the substrate. It is possible to prevent damage to the thin film, improve reliability, and improve the throughput of the manufacturing process.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an apparatus for manufacturing a thin film solar cell according to an embodiment of the present invention. FIG. 2 is a configuration diagram of an SCAF type thin film solar cell. FIG. 3 is a perspective view illustrating a schematic configuration of an SCAF type thin film solar cell. FIG. 4 is a diagram showing an outline of the manufacturing process of the SCAF type thin film solar cell.
21: Substrate unwinding roll, 24: Roll laminator, 31: Film substrate, 32, 33: Thermal release film, 40: Heat removal device, 41: Substrate winding roll, 50: Chemical etching device, 61, 71: Substrate, 62: Unit photoelectric conversion element, 63: Connection electrode layer, 64, 74: First electrode layer (lower electrode layer), 65, 75: Photoelectric conversion layer, 66, 76: Second electrode layer (transparent electrode layer) 67, 77: current collecting holes, 68, 78: connection holes, 73: third electrode layer, 79: fourth electrode layer, 81-83: etching tank, 91-93: cleaning tank.

Claims

A photoelectric conversion portion formed by sequentially laminating a first electrode layer, a photoelectric conversion layer, and a transparent electrode layer (second electrode layer) as a lower electrode layer on the surface of an electrically insulating substrate, and formed on the back surface of the substrate A third electrode layer and a fourth electrode layer as connection electrode layers are provided, and the photoelectric conversion portion and the connection electrode layer are patterned into unit portions while being shifted from each other, and formed in the photoelectric conversion layer formation region A method of manufacturing a thin-film solar cell in which unit photoelectric conversion portions (unit cells) that are patterned and adjacent to each other on the surface are electrically connected in series via a connection hole and a current collecting hole, the entire process from 1) 6) until, that is,
1) A step of forming a connection hole in the substrate, forming a first electrode layer on the substrate surface, and forming a third electrode layer on the back surface.
2) A step of opening current collecting holes in the substrate.
3) The process of forming a photoelectric converting layer on a 1st electrode layer, a connection hole, and a current collection hole inner surface.
4) A step of forming a transparent electrode layer on the photoelectric conversion layer excluding the connection hole forming region and on the photoelectric conversion layer on the inner surface of the current collecting hole.
5) A step of forming a fourth electrode layer on the third electrode layer, on the photoelectric conversion layer on the inner surface of the connection hole, and on the transparent electrode layer on the inner surface of the current collecting hole.
6) A step of patterning the photoelectric conversion part on the substrate surface and the connection electrode layer on the back surface of the substrate in a batch with a chemical etching apparatus (hereinafter referred to as chemical etching process) .
Further, before the chemical etching process, the non-processed part is masked with a heat release film, and after the chemical etching process, the thin film solar cell is removed by heating at a predetermined temperature. Manufacturing method.

A photoelectric conversion portion formed by sequentially laminating a first electrode layer, a photoelectric conversion layer, and a transparent electrode layer (second electrode layer) as a lower electrode layer on the surface of an electrically insulating substrate, and formed on the back surface of the substrate A third electrode layer and a fourth electrode layer as connection electrode layers are provided, and the photoelectric conversion portion and the connection electrode layer are patterned into unit portions while being shifted from each other, and formed in the photoelectric conversion layer formation region A method of manufacturing a thin-film solar cell in which unit photoelectric conversion portions (unit cells) that are patterned and adjacent to each other on the surface are electrically connected in series via a connection hole and a current collecting hole, The whole process from 1) to 6), that is,
1) A step of forming a connection hole in the substrate, forming a first electrode layer on the substrate surface, and forming a third electrode layer on the back surface.
2) A step of opening current collecting holes in the substrate.
3) The process of forming a photoelectric converting layer on a 1st electrode layer, a connection hole, and a current collection hole inner surface.
4) A step of forming a transparent electrode layer on the photoelectric conversion layer excluding the connection hole forming region and on the photoelectric conversion layer on the inner surface of the current collecting hole.
5) A step of forming a fourth electrode layer on the third electrode layer, on the photoelectric conversion layer on the inner surface of the connection hole, and on the transparent electrode layer on the inner surface of the current collecting hole.
6) A step of chemically etching the photoelectric conversion portion on the substrate surface and the connection electrode layer on the back surface of the substrate.
Furthermore, the substrate after completion of the steps 1) to 5) is unwound from an unwinding roll, and a heat release film in which a predetermined pattern is formed in advance on each side of the substrate is bonded to the substrate. subjecting said chemically etched into the substrate, followed after washing with water, the heat release film was removed by heating at a predetermined temperature, the patterned substrate, characterized in that the wound on the take-up roll Manufacturing method of thin film solar cell.

It is a manufacturing method of the thin film solar cell of Claim 1 or 2 , Comprising: In the case of the said chemical etching process, the process of a transparent electrode layer, a photoelectric converting layer, a 1st electrode layer, and a connection electrode layer differs, respectively. A method for producing a thin-film solar cell, which is performed using an etching solution.

A photoelectric conversion portion formed by sequentially laminating a first electrode layer, a photoelectric conversion layer, and a transparent electrode layer (second electrode layer) as a lower electrode layer on the surface of an electrically insulating substrate, and formed on the back surface of the substrate A third electrode layer and a fourth electrode layer as connection electrode layers are provided, and the photoelectric conversion portion and the connection electrode layer are patterned into unit portions while being shifted from each other, and formed in the photoelectric conversion layer formation region In the apparatus for manufacturing a thin-film solar cell in which unit photoelectric conversion parts (unit cells) that are patterned and adjacent to each other on the surface are electrically connected in series via a connection hole and a current collecting hole, the photoelectric conversion unit And a chemical laminator having a roll laminator for bonding a heat release film having a predetermined pattern formed on both surfaces of the substrate on which the connection electrode layer is formed, a plurality of etching tanks and a cleaning tank. Quenching device and a heating removing device for removing from a substrate by heating the heat-peelable film at a predetermined temperature, the manufacturing apparatus of a thin-film solar cell, comprising a roll conveyor device for the substrate.