JP4105863B2

JP4105863B2 - Method for manufacturing photoelectric conversion device

Info

Publication number: JP4105863B2
Application number: JP2001363646A
Authority: JP
Inventors: 豪京田; 潤福田; 久雄有宗
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2001-11-29
Filing date: 2001-11-29
Publication date: 2008-06-25
Anticipated expiration: 2021-11-29
Also published as: JP2003163358A

Description

【０００１】
【発明の属する技術分野】
本発明は結晶半導体粒子を用いた光電変換装置の製造方法に関し、特に太陽光発電に使用される光電変換装置の製造方法にする。
【０００２】
【従来の技術】
従来の結晶半導体粒子を用いた光電変換装置を図２に示す。
図２に示すように、特開昭６１−１２４１７９号公報には、第１のアルミニウム箔２５に開口を形成し、その開口にｐ形シリコン部２６の上にｎ形表皮部２７を持つシリコン球２６を結合し、球の裏側のｎ形表皮部２７を除去し、アルミニウム上に酸化物層２８をコーティングし、球裏側のｐ形シリコン部２６との接面上の酸化物層２８を除去し、このｐ型シリコン部２６と第２のアルミニウム箔２９とを固着する光電変換装置が開示されている。
【０００３】
【発明が解決しようとする課題】
しかしながら、図２に示す特開昭６１−１２４１７９号公報の光電変換装置では、ｐ形中心核２６の上にｎ形表皮部２７をもつシリコン球２６を第１のアルミニウム箔２５と接合させる際に、第１のアルミニウム箔２５に開口部を形成し、その開口部にシリコン球２６を落とし込む必要があるが、開口部全てにシリコン球２６を落とし込むことは製造上困難であり、またシリコン球２６の球径が小さくなればその困難性は更に増すという問題があった。
【０００４】
本発明は上記従来技術における問題点に鑑みてなされたものであり、その目的は、結晶半導体粒子の球径に関係なく基板表面に結晶半導体粒子を配設する光電変換装置の製造方法を提供することにある。
【０００５】
【課題を解決するための手段】
上記目的を達成するために、請求項１に係る光電変換装置の製造方法は、基板上に一導電型を呈する結晶半導体粒子を配設して固着し、この結晶半導体粒子上に他の導電型を呈する半導体層を形成する光電変換装置の製造方法において、前記基板表面に接着剤を塗布した後に前記基板の接着剤を塗布した側を下面にして多数の粒径が不均一の前記結晶半導体粒子に押し付けた後前記基板を引上げることによって、前記基板上に前記結晶半導体粒子を一時的に接着するとともに余分な前記結晶半導体粒子を落とし、その後荷重を結晶半導体粒子上にかけてこの基板と結晶半導体粒子の共晶温度以上で加熱することによって前記接着剤を揮散させながら若しくは揮散させた後に前記基板に前記結晶半導体粒子を固着し、さらに前記基板に固着しなかった前記結晶半導体粒子を取り除くことを特徴とする。
【０００６】
また、請求項２に係る光電変換装置の製造方法は、基板上に一導電型を呈する結晶半導体粒子を配設して固着し、この結晶半導体粒子上に他の導電型を呈する半導体層を形成する光電変換装置の製造方法において、前記基板上に粒径が不均一の前記結晶半導体粒子と接着剤とを混合したペーストを塗布することによって、前記基板上に前記結晶半導体粒子を一時的に接着し、その後荷重を結晶半導体粒子上にかけてこの基板と結晶半導体粒子の共晶温度以上で加熱することによって前記接着剤を揮散させながら若しくは揮散させた後に前記基板に前記結晶半導体粒子を固着し、さらに前記基板に固着しなかった前記結晶半導体粒子を取り除くことを特徴とする。
【０００７】
また、前記基板上に前記結晶半導体粒子を一時的に接着した後、ローラーで押し付けることを特徴とする。
【０００８】
また、前記接着剤が共晶温度より２５０℃低い温度から〜共晶温度で焼飛する有機樹脂材料から成り、酸素含有雰囲気下で加熱することを特徴とする。前記有機樹脂材料が、ブチラール樹脂、メチルセルロース、エチルセルロース、ポリビニルアルコール（ＰＶＡ）、ポリエチレングリコール（ＰＥＧ）のうちのいずれか一種以上から成ることを特徴とする。
【０００９】
また、前記接着剤が前記基板と前記結晶半導体粒子との固着温度以下の沸点を有する有機材料から成り、不活性雰囲気下で加熱することを特徴とする。その有機材料が、エチレングリコール、プロピレングリコール、トリメチレングリコール、１，３−ブチレングリコール、テトラメチレングリコール、ペンタメチレングリコール、へキシレングリコール、オクチレングリコール、グリセリン、パーフルオロケロシンのうちのいずれか一種以上から成ることを特徴とする。
【００１０】
また、前記結晶半導体粒子を前記基板上面からの投影面積比で７０％以上の密度で配設することを特徴とする。
【００１１】
また、前記基板がアルミニウムから成り、前記結晶半導体粒子がシリコンから成ることを特徴とする。
【００１２】
また、前記結晶半導体粒子の平均粒径が０．２〜０．６ｍｍであることを特徴とする。
【００１３】
上記のような方法で結晶半導体粒子を基板上に配設すると結晶半導体粒子を安定して並べることができる。
【００１４】
【発明の実施の形態】
以下、図面に基づいて本発明を詳細に説明する。
図１は本発明の光電変換装置の製造方法によって製造される光電変換装置を示す。
【００１５】
基板１はアルミニウム以上の融点の金属、セラミックであればよく、例えばアルミニウム、アルミニウム合金、鉄、ステンレス、ニッケル合金、アルミナ等が用いられる。そして基板１がアルミニウム以外の材料の場合は、その材料とアルミニウムから成る層１’の構成とし、アルミニウム層１’には更に第２の添加元素としてシリコン、マグネシウム、マンガン、クロム、チタン、ニッケル、亜鉛、銀、銅から選ばれた１種もしくは複数種の元素を添加してもよく、結晶半導体粒子２の固着時の溶融過多の防止を維持することができる。アルミニウム層１’の膜厚は、２０μｍ以上とする。２０μｍ未満では結晶半導体粒子２との固着を行う際に膜厚が不足して十分な固着ができなくなる。
【００１６】
基板１の表面に接着剤によって結晶半導体粒子２をランダムに一層以上一時的に接着させる。接着剤は結晶半導体粒子２を基板１の表面に付着させた状態を維持し、後述の処理で基板上から脱離しないようにする効果を持つ。接着剤を用いないと、基板１上に並べた結晶半導体粒子２が不安定な状態となって後述の処理で基板１上から脱離してしまい、結晶半導体粒子２を安定して配設することができなくなる。
【００１７】
基板１上に結晶半導体粒子２を一時的に接着させる方法として、第一の方法は、
基板１上に接着剤を塗布して接着剤層６を設け、基板１の接着剤層６を下面にして、バット等の平皿状のものに結晶半導体粒子を多数敷き詰めたところに押し付けることによって基板１に付着させ、基板１を引き上げて余分な結晶半導体粒子２を落とすことによって、結晶半導体粒子２を粒径の大小によらずに安定して１層以上接着することが可能となる。更に後述の加熱処理によって基板１に接しなかった結晶半導体粒子２は基板１と固着しないために、基板１を傾けて固着しなかった結晶半導体粒子２を取り除くことによって結晶半導体粒子２を基板１上に１層だけ配設することができる。
【００１８】
第二の方法は、接着剤と結晶半導体粒子を混合したペーストを基板１上にドクターブレード法等で塗布することによって、結晶半導体粒子２を粒径の大小によらずに安定して１層以上接着することが可能となる。更に後述の加熱処理によって基板１に接しなかった結晶半導体粒子２は基板１と固着しないために、基板１を傾けて固着しなかった結晶半導体粒子２を取り除くことによって結晶半導体粒子２を基板１上に１層だけ配設することができる。
【００１９】
上記２つの方法で基板１上に結晶半導体粒子２を接着した後、更にローラー等で押し付けることによって結晶半導体粒子２同士の隙間に更に結晶半導体粒子２を敷き詰めて基板１に接する結晶半導体粒子２の密度を向上させることもできる。
【００２０】
その後、一定の荷重を結晶半導体粒子２上にかけて、基板１の材料と結晶半導体粒子２の材料との共晶温度以上に加熱することによって、基板１と結晶半導体粒子２の合金層７を介して基板１と結晶半導体粒子２を固着させる。このとき大気中で加熱処理すると、前述の有機系の接着剤層６又は接着剤は分解して一部有機残渣を残しながら揮散し、残存した有機残渣が基板１の表面を覆うために基板１の表面酸化が一時的に防止され、固着が行われる。その後の加熱によって残存した有機残渣は完全に揮散する。
【００２１】
接着剤層６又は接着剤の材質としては共晶温度より２５０℃低い温度から〜共晶温度（基板１と結晶半導体粒子２との固着温度）で分解して揮散するものであればよく、基板１がアルミニウムから成り、結晶半導体粒子２がシリコンから成る場合には３２７〜５７７℃の範囲となり、ブチラール樹脂、メチルセルロース、エチルセルロース、ポリビニルアルコール（ＰＶＡ）、ポリエチレングリコール（ＰＥＧ）等の樹脂を溶媒で溶解させた有機系の樹脂が上げられ、分解して揮散する温度が共晶温度より２５０℃以上低い温度では共晶温度までに有機成分が一時的にも残存しないために共晶温度に至る前に基板１の表面が酸化してしまい、酸化膜のために基板１と結晶半導体粒子２との共晶ができなくなってしまう。
【００２２】
また、窒素又はアルゴン等の不活性ガス雰囲気下で加熱処理を行う場合は、有機系の接着剤層６又は接着剤は共晶温度未満で完全に蒸発することで揮散し、基板１と結晶半導体粒子２の固着界面で有機残渣を残すことがなく、良好に固着が行われる。
【００２３】
接着剤層６又は接着剤の材質としては基板１と結晶半導体粒子２との固着温度以下の沸点を有し、基板１上から流れ出さないためのある程度の粘性があるものであればよく、エチレングリコール（ｂｐ．：１９９℃、粘性率：２５ｃｐ）、プロピレングリコール（ｂｐ．：１８７℃、粘性率：５６ｃｐ）、トリメチレングリコール（ｂｐ．：２１４℃、粘性率：０．４６Ｓｔ）、１，３−ブチレングリコール（ｂｐ．：２０７℃、粘性率：１３０ｃｐ）、テトラメチレングリコール（ｂｐ．：２２９℃、粘性率：８９ｃｐ）、ペンタメチレングリコール（ｂｐ．：２４２℃、粘性率：１２８ｃｐ）、へキシレングリコール（ｂｐ．：１９７℃、粘性率：３４ｃｐ）、オクチレングリコール（ｂｐ．：２４３℃、粘性率：３２３ｃｐ）、グリセリン（ｂｐ．：２９０℃、粘性率：１４１２ｃｐ）、パーフルオロケロシン（ｂｐ．：２１５℃）等の有機材料が上げられ、沸点を有さず酸素雰囲気下で分解して揮散する材料では、共晶温度になっても有機成分が残存してしまい、残存成分のために基板１と結晶半導体粒子２との共晶ができなくなってしまう。
【００２４】
接着剤層６の形成方法は、スクリーン印刷法、ドクターブレード法、スプレー法、ディッピング法等で基板１の表面上に１０〜１００μｍの厚みに塗布する。
【００２５】
ここで、結晶半導体粒子２の配設密度は、配設された結晶半導体粒子２の基板１上面から見た投影面積比で示される。最大で９０．６％の投影面積比となるが、７０％以下になると光電変換効率が急激に減少するため、結晶半導体粒子２の充填密度を示す投影面積比は７０％以上がよく、上記配設方法によって投影面積比が７０％以上の配設が可能となる。
【００２６】
基板１上には、前述のように第一導電型の結晶半導体粒子２を多数配設する。この結晶半導体粒子２は、Ｓｉにｐ形を呈するＢ、Ａｌ、Ｇａ等、又はｎ形を呈するＰ、Ａｓ等が微量元素含まれているものである。結晶半導体粒子２の形状としては多角形を持つもの、曲面を持つもの等があり、粒径分布としては不均一とし、均一の場合は粒径を揃えるための工程が必要になるため、より安価にするためには不均一の方が有利である。更に凸曲面を持つことによって光の光線角度の依存性も小さい。結晶半導体粒子２の粒径としては、０．２〜０．８ｍｍがよく、０．８ｍｍを越えると切削部も含めた従来の結晶板型の太陽電池のシリコン使用量と変わらなくなり、結晶半導体粒子を用いるメリットがなくなる。また、０．２ｍｍよりも小さいと基板１へのアッセンブルがしにくくなるという別の問題が発生してしまう。より好適にはシリコン使用量の関係から０．２〜０．６ｍｍがよい。
【００２７】
基板１上には、絶縁体３が設けられる。この絶縁体３は、正極と負極の分離を行うための絶縁材料からなり、例えばＳｉＯ₂、Ａｌ₂Ｏ₃、ＰｂＯ、Ｂ₂Ｏ₃、ＺｎＯ等を任意な成分とするガラススラリー、或いはポリイミド樹脂や耐熱性エポキシ樹脂等の有機材料、或いは基板１の表面を陽極酸化させて形成した絶縁酸化膜を用いた絶縁体等がある。ガラススラリーを用いる場合は、基板１と結晶半導体粒子２との間でオーミック固着を取る際の加熱温度未満で融解して結晶半導体粒子２を部分的に覆う特性を持つものである。なお、結晶半導体粒子２上に後述の結晶半導体層４を設けてｐｎ接合を形成する際に、ｐｎ接合面積を確保するために絶縁体３を形成する前に、結晶半導体粒子２の上面に上面コート層８を設けて結晶半導体粒子２の上面に絶縁体３が形成されないようにしてもよい。上面コート層８の材料としては絶縁体３をはじく材料であればよく、炭素系、窒化硼素系、有機系のもがある。絶縁体３を形成した後は、上面コート層８をブラッシングや洗浄等で除去する。
【００２８】
絶縁体３および結晶半導体粒子２上には表面電極を兼ねる第二導電形の結晶半導体層４を設け、結晶半導体粒子２上にｐｎ接合を形成する。この結晶半導体層４は、気相成長法等により例えばシラン化合物の気相にｎ形を呈するリン系化合物の気相、又はｐ形を呈するホウ素系化合物の気相を微量導入して形成する。なお、結晶半導体層４は、単結晶質、多結晶質、又は微結晶質を含むものであればよい。また、結晶半導体層４は電極の役目も兼ね備えるならば、導電性の兼ね合いから層中の微量元素の濃度は高くてもよく、例えば１×１０¹⁶〜１０²¹ａｔｍ／ｃｍ³程度である。
【００２９】
第二導電形の結晶半導体層４上には保護層５を設ける。保護層５は光学的に透明の特性を持つものがよく、ＣＶＤ法やＰＶＤ法等によって例えば酸化珪素、酸化セシウム、酸化アルミニウム、窒化珪素、酸化チタン、ＳｉＯ₂−ＴｉＯ₂、酸化タンタル、酸化イットリウム等を単一組成又は複数組成で単層又は組み合わせて結晶半導体層４上に形成する。保護層５に電極の役目を担わせることも可能であり、その際はＳｎＯ₂、Ｉｎ₂Ｏ₃、ＩＴＯ、ＺｎＯ等の透明導電性の材料を用いればよい。
【００３０】
なお、保護層５の膜厚を最適化すれば反射防止膜としての機能も期待できる。
【００３１】
直列抵抗値を低くするために結晶半導体層４又は保護層５の上に一定間隔のフィンガーやバスバーといったパターン電極を設け、変換効率を向上させることも可能である。
【００３２】
【実施例】
次に、本発明の光電変換装置の製造方法の具体例を説明する。
〔例１〕
アルミニウム合金をニッケル合金基材上に５０μｍの厚みで冷間圧着で形成した基板１を用い、表１に示す材料から成る接着剤層をスクリーン印刷又はドクターブレードで塗布した。そしてバットに乗せた直径約０．２〜０．６ｍｍのｐ形シリコン粒子に基板の接着剤層を下面側にしてｐ形シリコン粒子に押し付けて基板の接着剤層に付着させ、その後基板１を傾けて余分なｐ形シリコン粒子を取り除いた。その後、加熱処理時にｐ形シリコン粒子が動かないように一定の荷重をかけて押し付けた状態で、大気中の５７７℃（アルミニウムとシリコンの共晶温度）以上の温度で５〜３０分加熱してシリコン粒子をアルミニウム合金に固着させた（実施例１〜４）。
【００３３】
なお、比較例１として、基板上に接着剤層を塗布しなかった以外は、実施例１〜４と同様の処理を行った。
【００３４】
また、実施例５〜８として、実施例１〜４で用いた接着剤層の材料にｐ形シリコン粒子を混合させたペーストを基板上にドクターブレード法で塗布してｐ形シリコン粒子を基板上に一時的に接着して実施例１〜４と同様の処理を行って固着させた。
【００３５】
なお、比較例２として、接着剤でペースト化しなかった以外は実施例５〜８と同様の処理を行った。
【００３６】
更に、実施例１、３、５、７でｐ形シリコン粒子を基板上に一時的に接着してテフロン製のローラーで押し付けた後、実施例１〜４と同様の処理を行って固着させた試料を実施例９〜１２とした。
【００３７】
以上のようにしてｐ形シリコン粒子を基板上に配設した試料の固着処理前後のシリコン粒子の投影面積比を測定した。その結果を表１にまとめる。
【００３８】
【表１】

【００３９】
比較例１は、接着剤層を形成しなかったために、製法上ｐ形シリコン粒子を基板上に全く固着できなかった。
【００４０】
比較例２は、ｐ形シリコン粒子がその後の作業で基板から脱離してしまい、固着前の投影面積比が５４％と悪い状況となった。
【００４１】
一方、実施例１〜８では、接着剤層の形成又は接着剤を使ったペーストを用いてｐ形シリコン粒子を７０％以上の投影面積比で基板上に接着することができ、固着処理後もｐ形シリコン粒子の投影面積比を維持することができた。
【００４２】
更に、ローラーで押し付けた実施例９〜１２では、ｐ形シリコン粒子の投影面積比が８０％以上であり、ｐ形シリコン粒子が基板上に更に密に固着することができた。
〔例２〕
実施例１〜４と同様の方法で、表２に示す材料から成る各接着剤層を用いてｐ形シリコン粒子を基板上に接着させ、大気中でｐ形シリコン粒子を基板に固着させたときの、固着処理前後でのシリコン粒子の投影面積比を測定した。その結果を表２にまとめる。
【００４３】
接着剤層の材料として分解による揮散温度が３２７〜５７７℃（アルミニウムとシリコンの共晶温度）であるブチラール樹脂、メチルセルロース、エチルセルロース、ポリビニルアルコール（ＰＶＡ）、ポリエチレングリコール（ＰＥＧ）を有機溶媒又は水で溶解させ、スクリーン印刷又はドクターブレードで塗布した。なお、比較例としては、接着剤層の材料として蒸発による揮散温度（沸点）が３２７℃未満のカルビトール（ｂｐ．：１９６℃、２−（２−ｅｔｈｏｘｙｅｔｈｏｘｙ）ｅｔｈａｎｏｌ）、パーフルオロケロシン（ｂｐ．：２１５℃）を用いた。
【００４４】
【表２】

【００４５】
どの試料も固着前はｐ形シリコン粒子を７０％以上の投影面積比で基板上に接着することができた。
【００４６】
しかしながら、比較例３、４では、固着後の状態において、シリコン粒子を基板に固着できないものがあり、ｐ形シリコン粒子の投影面積比が低いものとなった。これは、接着剤層の材料の揮散温度（沸点）が３２７℃未満であり、固着時の温度で接着剤層の材料がすぐに揮散（蒸発）してしまったために、基板のアルミニウム合金の表面に酸化膜が形成され、基板のアルミニウムとシリコン粒子の共晶の形成が阻害されたものと考えられる。
【００４７】
一方、実施例１３〜２２では、シリコン粒子の粒子径が０．２ｍｍ或いは０．６ｍｍでもｐ形シリコン粒子の投影面積比が固着前の状態を維持することができた。このことは、固着時の温度で基板のアルミニウム合金の表面を接着剤層が覆っているために表面に酸化膜が形成されず、基板のアルミニウムとシリコン粒子の共晶が良好に形成されたためと考えられる。
〔例３〕
実施例１〜４と同様の方法で、表３に示す材料から成る各接着剤層を用いてｐ形シリコン粒子を基板上に接着させ、窒素又はアルゴン等の不活性ガス雰囲気下でｐ形シリコン粒子を基板に固着させたときの、固着処理前後でのシリコン粒子の投影面積比を測定した。その結果を表３にまとめる。
【００４８】
接着剤層の材料として沸点が基板と結晶半導体粒子との固着温度以下で、ある程度の粘性を持つエチレングリコール、プロピレングリコール、トリメチレングリコール、１，３−ブチレングリコール、テトラメチレングリコール、ペンタメチレングリコール、へキシレングリコール、オクチレングリコール、グリセリン、パーフルオロケロシンをスクリーン印刷又はドクターブレードで塗布した。なお、比較例としては、接着剤層の材料として沸点を持たず酸素雰囲気下で分解して揮散する有機樹脂材料としてブチラール樹脂、メチルセルロース、エチルセルロース、ポリビニルアルコール（ＰＶＡ）を有機溶媒で溶解させたものを用いた。
【００４９】
【表３】

【００５０】
どの試料も固着前ではｐ形シリコン粒子を７０％以上の投影面積比で基板上に接着することができた。
【００５１】
しかしながら、比較例５、６、７では、固着後の状態において、シリコン粒子が基板に固着できないものがあり、ｐ形シリコン粒子の投影面積比が低いものとなった。
【００５２】
これは、接着剤層の材料が沸点を持たず、酸素雰囲気下で分解して揮散する材料であるために、固着時の温度で接着剤層の材料が残存してしまい、基板のアルミニウム合金の表面に残存膜が形成され、基板のアルミニウムとシリコン粒子の共晶の形成が阻害されたものと考えられる。
【００５３】
一方、実施例２３〜４２では、シリコン粒子の粒子径が０．２ｍｍ或いは０．６ｍｍでもｐ形シリコン粒子の投影面積比が固着前の状態を維持することができた。このことは、ある程度の粘性を持った接着剤層を用いることによってシリコン粒子を密に固定することが可能となり、更に固着時の温度未満で蒸発して残存成分を残さないために、基板のアルミニウムとシリコン粒子の共晶が良好に形成されたためと考えられる。
【００５４】
以上のことから、本発明の光電変換装置の製造方法によれば、高い投影面積比で、シリコン粒子を基板上に配設することができる光電変換装置を製造することができることが確認できた。
【００５５】
【発明の効果】
以上のように、本発明の光電変換装置の製造方法によれば、基板表面に接着剤を塗布した後に基板の接着剤を塗布した側を下面にして多数の粒径が不均一の結晶半導体粒子に押し付けた後基板を引上げることによって、基板上に結晶半導体粒子を一時的に接着するとともに余分な結晶半導体粒子を落とし、その後荷重を結晶半導体粒子上にかけてこの基板と結晶半導体粒子の共晶温度以上で加熱することによって上記接着剤を揮散させながら若しくは揮散させた後に上記基板に上記結晶半導体粒子を固着し、さらに基板に固着しなかった結晶半導体粒子を取り除いたり、基板上に粒径が不均一の結晶半導体粒子と接着剤とを混合したペーストを塗布することによって、基板上に結晶半導体粒子を一時的に接着し、その後荷重を結晶半導体粒子上にかけてこの基板と結晶半導体粒子の共晶温度以上で加熱することによって上記接着剤を揮散させながら若しくは揮散させた後に上記基板に上記結晶半導体粒子を固着し、さらに基板に固着しなかった結晶半導体粒子を取り除くことから、基板上面に結晶半導体粒子を高い密度で配設することが可能となり、よって高い変換効率を維持することができる光電変換装置を提供することができる。
【図面の簡単な説明】
【図１】本発明の方法によって製造される光電変換装置の一実施形態を示す断面図である。
【図２】従来の光電変換装置を示す断面図である。
【符号の説明】
１・・・・基板
１’・・・アルミニウム層
２・・・・第一導電形結晶質半導体粒子
３・・・・絶縁体層
４・・・・第二導電形半導体層（他方の電極層）
５・・・・保護層
６・・・・接着剤層
７・・・・基板と結晶質半導体粒子の合金層
８・・・・上面コート層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a photoelectric conversion device using crystalline semiconductor particles, and particularly to a method for manufacturing a photoelectric conversion device used for photovoltaic power generation.
[0002]
[Prior art]
A conventional photoelectric conversion device using crystalline semiconductor particles is shown in FIG.
As shown in FIG. 2, Japanese Patent Laid-Open No. 61-124179 discloses a silicon sphere having an opening formed in a first aluminum foil 25 and an n-type skin portion 27 on a p-type silicon portion 26 in the opening. 26, the n-type skin 27 on the back side of the sphere is removed, the oxide layer 28 is coated on aluminum, and the oxide layer 28 on the contact surface with the p-type silicon part 26 on the back side of the sphere is removed. A photoelectric conversion device for fixing the p-type silicon portion 26 and the second aluminum foil 29 is disclosed.
[0003]
[Problems to be solved by the invention]
However, in the photoelectric conversion device disclosed in Japanese Patent Application Laid-Open No. 61-124179 shown in FIG. 2, when the silicon sphere 26 having the n-type skin portion 27 on the p-type central core 26 is joined to the first aluminum foil 25. It is necessary to form an opening in the first aluminum foil 25 and drop the silicon sphere 26 into the opening. However, it is difficult to drop the silicon sphere 26 into the entire opening. There is a problem that the difficulty increases as the sphere diameter decreases.
[0004]
The present invention has been made in view of the above problems in the prior art, and an object of the present invention is to provide a method of manufacturing a photoelectric conversion device in which crystal semiconductor particles are arranged on a substrate surface regardless of the spherical diameter of the crystal semiconductor particles. There is.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a method of manufacturing a photoelectric conversion device according to claim 1 is provided by arranging and fixing a crystal semiconductor particle having one conductivity type on a substrate, and another conductivity type on the crystal semiconductor particle. In the method of manufacturing a photoelectric conversion device for forming a semiconductor layer exhibiting the above, the crystal semiconductor particles having a large number of non-uniform particle sizes with the adhesive-coated side of the substrate being the lower surface after the adhesive is applied to the substrate surface The crystal semiconductor particles are temporarily bonded onto the substrate by dropping the substrate after being pressed onto the substrate, and excess crystal semiconductor particles are dropped , and then a load is applied onto the crystal semiconductor particles to apply the substrate and the crystal semiconductor particles. of fixed said crystalline semiconductor particles on the substrate after being or volatilization while volatilizing the adhesive by heating at a eutectic temperature or higher, Do further secured to said substrate Characterized in that removing the crystal semiconductor particles Tsu.
[0006]
According to a second aspect of the present invention, there is provided a method for manufacturing a photoelectric conversion device, wherein a crystalline semiconductor particle exhibiting one conductivity type is disposed and fixed on a substrate, and a semiconductor layer exhibiting another conductivity type is formed on the crystal semiconductor particle. in the manufacturing method of a photoelectric conversion device that, by applying a paste the particle size on the substrate is obtained by mixing a bonding agent and the crystalline semiconductor particles of non-uniform, temporarily bonding said crystalline semiconductor particles on the substrate Then, the crystal semiconductor particles are fixed to the substrate while volatilizing or volatilizing the adhesive by applying a load on the crystal semiconductor particles and heating at a temperature equal to or higher than the eutectic temperature of the substrate and the crystal semiconductor particles. The crystalline semiconductor particles that have not adhered to the substrate are removed .
[0007]
In addition, the crystalline semiconductor particles are temporarily bonded onto the substrate and then pressed with a roller.
[0008]
The adhesive is made of an organic resin material burned off at a temperature lower than the eutectic temperature by 250 ° C. to a eutectic temperature, and is heated in an oxygen-containing atmosphere. The organic resin material is composed of one or more of butyral resin, methylcellulose, ethylcellulose, polyvinyl alcohol (PVA), and polyethylene glycol (PEG).
[0009]
The adhesive is made of an organic material having a boiling point not higher than a fixing temperature between the substrate and the crystalline semiconductor particles, and is heated in an inert atmosphere. The organic material is at least one of ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butylene glycol, tetramethylene glycol, pentamethylene glycol, hexylene glycol, octylene glycol, glycerin, and perfluorokerosine. It is characterized by comprising.
[0010]
Further, the crystalline semiconductor particles are arranged at a density of 70% or more in terms of a projected area ratio from the upper surface of the substrate.
[0011]
Further, the substrate is made of aluminum, and the crystalline semiconductor particles are made of silicon.
[0012]
The average particle size of the crystalline semiconductor particles is 0.2 to 0.6 mm.
[0013]
When the crystalline semiconductor particles are arranged on the substrate by the method as described above, the crystalline semiconductor particles can be stably arranged.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a photoelectric conversion device manufactured by the method for manufacturing a photoelectric conversion device of the present invention.
[0015]
The substrate 1 may be a metal or ceramic having a melting point higher than that of aluminum, and for example, aluminum, aluminum alloy, iron, stainless steel, nickel alloy, alumina, or the like is used. When the substrate 1 is made of a material other than aluminum, a layer 1 ′ made of the material and aluminum is used, and the aluminum layer 1 ′ further includes silicon, magnesium, manganese, chromium, titanium, nickel, One or more elements selected from zinc, silver and copper may be added, and the prevention of excessive melting at the time of fixing the crystalline semiconductor particles 2 can be maintained. The film thickness of the aluminum layer 1 ′ is 20 μm or more. If the thickness is less than 20 μm, the film thickness is insufficient when the crystalline semiconductor particles 2 are fixed, and sufficient fixing cannot be performed.
[0016]
One or more crystal semiconductor particles 2 are temporarily adhered to the surface of the substrate 1 at random by an adhesive. The adhesive maintains the state in which the crystalline semiconductor particles 2 are attached to the surface of the substrate 1 and has an effect of preventing the crystalline semiconductor particles 2 from being detached from the substrate in the processing described later. If an adhesive is not used, the crystalline semiconductor particles 2 arranged on the substrate 1 become unstable and are detached from the substrate 1 in the process described later, so that the crystalline semiconductor particles 2 are stably disposed. Can not be.
[0017]
As a method for temporarily adhering the crystalline semiconductor particles 2 on the substrate 1, the first method is:
The substrate is formed by applying an adhesive on the substrate 1 to provide an adhesive layer 6, pressing the adhesive layer 6 of the substrate 1 on the lower surface, and pressing a large number of crystalline semiconductor particles on a flat dish such as a bat. By attaching it to 1 and pulling up the substrate 1 and dropping excess crystal semiconductor particles 2, it becomes possible to stably adhere one or more layers of the crystal semiconductor particles 2 regardless of the particle size. Further, since the crystalline semiconductor particles 2 that are not in contact with the substrate 1 by the heat treatment described later do not adhere to the substrate 1, the crystalline semiconductor particles 2 are removed from the substrate 1 by removing the crystalline semiconductor particles 2 that are not adhered by tilting the substrate 1. Only one layer can be provided.
[0018]
In the second method, a paste in which an adhesive and crystal semiconductor particles are mixed is applied onto the substrate 1 by a doctor blade method or the like, so that the crystal semiconductor particles 2 can be stably formed in one or more layers regardless of the size. It becomes possible to adhere. Further, since the crystalline semiconductor particles 2 that are not in contact with the substrate 1 by the heat treatment described later do not adhere to the substrate 1, the crystalline semiconductor particles 2 are removed from the substrate 1 by removing the crystalline semiconductor particles 2 that are not adhered by tilting the substrate 1. Only one layer can be provided.
[0019]
After the crystal semiconductor particles 2 are bonded onto the substrate 1 by the above two methods, the crystal semiconductor particles 2 are further spread over the gaps between the crystal semiconductor particles 2 by pressing with a roller or the like, and the crystal semiconductor particles 2 in contact with the substrate 1 The density can also be improved.
[0020]
Thereafter, a certain load is applied to the crystalline semiconductor particles 2 and heated to a temperature equal to or higher than the eutectic temperature of the material of the substrate 1 and the material of the crystalline semiconductor particles 2, thereby passing through the alloy layer 7 of the substrate 1 and the crystalline semiconductor particles 2. The substrate 1 and the crystalline semiconductor particles 2 are fixed. When the heat treatment is performed in the atmosphere at this time, the organic adhesive layer 6 or the adhesive described above is decomposed and volatilized while leaving a part of the organic residue, and the remaining organic residue covers the surface of the substrate 1 in order to cover the surface of the substrate 1. Oxidation of the surface is temporarily prevented and fixing is performed. The organic residue remaining by the subsequent heating is completely volatilized.
[0021]
The material of the adhesive layer 6 or the adhesive may be any material that decomposes and volatilizes from a temperature lower than the eutectic temperature by 250 ° C. to the eutectic temperature (fixing temperature between the substrate 1 and the crystalline semiconductor particles 2). When 1 is made of aluminum and the crystalline semiconductor particles 2 are made of silicon, the temperature ranges from 327 to 577 ° C., and a resin such as butyral resin, methylcellulose, ethylcellulose, polyvinyl alcohol (PVA), polyethylene glycol (PEG) is dissolved in a solvent. When the temperature of the decomposed and volatilized organic resin is raised by 250 ° C. or more lower than the eutectic temperature, no organic components remain temporarily up to the eutectic temperature. The surface of the substrate 1 is oxidized, and the eutectic of the substrate 1 and the crystalline semiconductor particles 2 becomes impossible due to the oxide film.
[0022]
In addition, when heat treatment is performed in an inert gas atmosphere such as nitrogen or argon, the organic adhesive layer 6 or the adhesive is volatilized by being completely evaporated below the eutectic temperature, and the substrate 1 and the crystalline semiconductor Fixation is performed satisfactorily without leaving an organic residue at the fixing interface of the particles 2.
[0023]
As the material of the adhesive layer 6 or the adhesive, any material may be used as long as it has a boiling point not higher than the fixing temperature between the substrate 1 and the crystalline semiconductor particles 2 and has a certain degree of viscosity so as not to flow out from the substrate 1. Glycol (bp .: 199 ° C., viscosity: 25 cp), propylene glycol (bp .: 187 ° C., viscosity: 56 cp), trimethylene glycol (bp .: 214 ° C., viscosity: 0.46 St), 1, 3 -Butylene glycol (bp .: 207 ° C, viscosity: 130 cp), tetramethylene glycol (bp .: 229 ° C, viscosity: 89 cp), pentamethylene glycol (bp .: 242 ° C, viscosity: 128 cp), hexylene Glycol (bp .: 197 ° C., viscosity: 34 cp), octylene glycol (bp .: 243 ° C., viscosity: 323 cp), glyce (Bp .: 290 ° C., viscosity: 1412 cp), perfluorokerosene (bp .: 215 ° C.), and other organic materials that have no boiling point and decompose and volatilize in an oxygen atmosphere. Even when the crystallization temperature is reached, the organic component remains, and the eutectic between the substrate 1 and the crystalline semiconductor particles 2 becomes impossible due to the remaining component.
[0024]
The adhesive layer 6 is formed by applying a thickness of 10 to 100 μm on the surface of the substrate 1 by a screen printing method, a doctor blade method, a spray method, a dipping method or the like.
[0025]
Here, the arrangement density of the crystalline semiconductor particles 2 is indicated by a projected area ratio of the arranged crystalline semiconductor particles 2 as viewed from the upper surface of the substrate 1. Although the projected area ratio is 90.6% at the maximum, the photoelectric conversion efficiency rapidly decreases when the ratio is 70% or less. Therefore, the projected area ratio indicating the packing density of the crystalline semiconductor particles 2 is preferably 70% or more. Depending on the installation method, it is possible to dispose the projection area ratio of 70% or more.
[0026]
A large number of first-conductivity-type crystalline semiconductor particles 2 are arranged on the substrate 1 as described above. The crystalline semiconductor particles 2 contain trace elements such as B, Al, Ga, etc. exhibiting p-type in Si, or P, As, etc. exhibiting n-type. The crystalline semiconductor particle 2 has a polygonal shape, a curved surface, etc., and the particle size distribution is non-uniform, and if it is uniform, a process for aligning the particle size is required, so it is cheaper. In order to achieve this, non-uniformity is advantageous. Furthermore, by having a convex curved surface, the dependency of the light beam angle is small. The particle size of the crystalline semiconductor particles 2 is preferably 0.2 to 0.8 mm. If the particle size exceeds 0.8 mm, the amount of silicon used in the conventional crystal plate type solar cell including the cut portion is not changed. The advantage of using is lost. On the other hand, if it is smaller than 0.2 mm, another problem that it is difficult to assemble the substrate 1 occurs. More preferably, the thickness is 0.2 to 0.6 mm in view of the amount of silicon used.
[0027]
An insulator 3 is provided on the substrate 1. The insulator 3 is made of an insulating material for separating the positive electrode and the negative electrode. For example, a glass slurry or polyimide resin containing SiO ₂ , Al ₂ O ₃ , PbO, B ₂ O ₃ , ZnO or the like as an optional component. Or an organic material such as a heat-resistant epoxy resin, or an insulator using an insulating oxide film formed by anodizing the surface of the substrate 1. When the glass slurry is used, it has a characteristic of partially covering the crystalline semiconductor particles 2 by melting at a temperature lower than the heating temperature at the time of taking ohmic fixation between the substrate 1 and the crystalline semiconductor particles 2. When a crystal semiconductor layer 4 (to be described later) is provided on the crystal semiconductor particle 2 to form a pn junction, the top surface of the crystal semiconductor particle 2 is formed on the upper surface of the crystal semiconductor particle 2 before forming the insulator 3 in order to secure a pn junction area. The coat layer 8 may be provided so that the insulator 3 is not formed on the upper surface of the crystalline semiconductor particles 2. The material of the top coat layer 8 may be any material that repels the insulator 3 and may be carbon-based, boron nitride-based, or organic-based. After the insulator 3 is formed, the upper surface coat layer 8 is removed by brushing or washing.
[0028]
On the insulator 3 and the crystal semiconductor particles 2, a second conductivity type crystal semiconductor layer 4 also serving as a surface electrode is provided, and a pn junction is formed on the crystal semiconductor particles 2. The crystalline semiconductor layer 4 is formed by introducing a small amount of a vapor phase of a phosphorus compound exhibiting an n-type or a boron compound exhibiting a p-type into a vapor phase of a silane compound, for example, by vapor phase growth. Note that the crystalline semiconductor layer 4 only needs to include single crystal, polycrystalline, or microcrystalline. Further, if the crystalline semiconductor layer 4 also serves as an electrode, the concentration of trace elements in the layer may be high from the viewpoint of conductivity, for example, about 1 × 10 ¹⁶ to 10 ²¹ atm / cm ³ .
[0029]
A protective layer 5 is provided on the crystalline semiconductor layer 4 of the second conductivity type. The protective layer 5 preferably has an optically transparent characteristic. For example, silicon oxide, cesium oxide, aluminum oxide, silicon nitride, titanium oxide, SiO ₂ —TiO ₂ , tantalum oxide, yttrium oxide are formed by CVD or PVD. Are formed on the crystalline semiconductor layer 4 by a single layer or a combination of a single composition or a plurality of compositions. The protective layer 5 can also serve as an electrode. In this case, a transparent conductive material such as SnO ₂ , In ₂ O ₃ , ITO, ZnO may be used.
[0030]
In addition, if the film thickness of the protective layer 5 is optimized, a function as an antireflection film can be expected.
[0031]
In order to reduce the series resistance value, pattern electrodes such as fingers and bus bars at regular intervals may be provided on the crystalline semiconductor layer 4 or the protective layer 5 to improve the conversion efficiency.
[0032]
【Example】
Next, the specific example of the manufacturing method of the photoelectric conversion apparatus of this invention is demonstrated.
[Example 1]
An adhesive layer made of the material shown in Table 1 was applied by screen printing or a doctor blade using a substrate 1 in which an aluminum alloy was formed on a nickel alloy base material by cold pressing with a thickness of 50 μm. Then, the p-type silicon particles having a diameter of about 0.2 to 0.6 mm placed on the bat are attached to the p-type silicon particles by pressing the p-type silicon particles with the adhesive layer of the substrate on the lower surface side, and then the substrate 1 is attached. Tilt to remove excess p-type silicon particles. Then, in a state of pressing with a certain load so that the p-type silicon particles do not move during the heat treatment, heat at 577 ° C. (eutectic temperature of aluminum and silicon) in the atmosphere for 5 to 30 minutes. Silicon particles were fixed to an aluminum alloy (Examples 1 to 4).
[0033]
In addition, as the comparative example 1, the process similar to Examples 1-4 was performed except not having apply | coated the adhesive bond layer on the board | substrate.
[0034]
Moreover, as Examples 5-8, the paste which mixed the p-type silicon particle with the material of the adhesive layer used in Examples 1-4 was apply | coated to the board | substrate by the doctor blade method, and p-type silicon particle was carried out on a board | substrate. Then, the same treatment as in Examples 1 to 4 was performed and adhered.
[0035]
In addition, as Comparative Example 2, the same treatment as in Examples 5 to 8 was performed except that the paste was not formed with an adhesive.
[0036]
Further, in Examples 1, 3, 5, and 7, the p-type silicon particles were temporarily adhered onto the substrate and pressed with a Teflon roller, and then fixed by performing the same process as in Examples 1 to 4. The sample was made into Examples 9-12.
[0037]
As described above, the projected area ratio of the silicon particles before and after fixing the sample in which the p-type silicon particles were arranged on the substrate was measured. The results are summarized in Table 1.
[0038]
[Table 1]

[0039]
In Comparative Example 1, since no adhesive layer was formed, p-type silicon particles could not be fixed on the substrate at all due to the manufacturing method.
[0040]
In Comparative Example 2, the p-type silicon particles were detached from the substrate in the subsequent work, and the projected area ratio before fixing was 54%, which was a bad situation.
[0041]
On the other hand, in Examples 1 to 8, p-type silicon particles can be bonded onto a substrate with a projected area ratio of 70% or more using an adhesive layer formation or a paste using an adhesive, and even after the fixing process. The projected area ratio of the p-type silicon particles could be maintained.
[0042]
Further, in Examples 9 to 12 pressed with a roller, the projected area ratio of the p-type silicon particles was 80% or more, and the p-type silicon particles were able to adhere more densely on the substrate.
[Example 2]
When p-type silicon particles are adhered to the substrate using the adhesive layers made of the materials shown in Table 2 in the same manner as in Examples 1 to 4, and the p-type silicon particles are fixed to the substrate in the atmosphere. The projected area ratio of silicon particles before and after the fixing treatment was measured. The results are summarized in Table 2.
[0043]
Butylal resin, methylcellulose, ethylcellulose, polyvinyl alcohol (PVA), and polyethylene glycol (PEG) having a volatilization temperature due to decomposition of 327-577 ° C. (eutectic temperature of aluminum and silicon) as materials for the adhesive layer with an organic solvent or water Dissolved and applied by screen printing or doctor blade. In addition, as a comparative example, as a material for the adhesive layer, carbitol (bp .: 196 ° C., 2- (2-ethoxyethyl) ethanol) having a volatilization temperature (boiling point) by evaporation of less than 327 ° C., perfluorokerosine (bp. : 215 ° C).
[0044]
[Table 2]

[0045]
All samples were able to adhere p-type silicon particles on the substrate with a projected area ratio of 70% or more before fixing.
[0046]
However, in Comparative Examples 3 and 4, there were those in which the silicon particles could not be fixed to the substrate in the state after fixing, and the projected area ratio of the p-type silicon particles was low. This is because the volatilization temperature (boiling point) of the material of the adhesive layer is less than 327 ° C., and the material of the adhesive layer immediately volatilizes (evaporates) at the fixing temperature. It is considered that an oxide film was formed on the substrate, and the formation of a eutectic of aluminum and silicon particles on the substrate was hindered.
[0047]
On the other hand, in Examples 13 to 22, even when the particle diameter of the silicon particles was 0.2 mm or 0.6 mm, the projected area ratio of the p-type silicon particles could maintain the state before fixing. This is because the surface of the aluminum alloy of the substrate is covered with the adhesive layer at the temperature at the time of fixation, so that an oxide film is not formed on the surface, and the eutectic of the aluminum and silicon particles of the substrate is well formed. Conceivable.
[Example 3]
In the same manner as in Examples 1 to 4, p-type silicon particles were adhered to the substrate using each adhesive layer made of the materials shown in Table 3, and p-type silicon was used in an inert gas atmosphere such as nitrogen or argon. The projected area ratio of the silicon particles before and after the fixing treatment when the particles were fixed to the substrate was measured. The results are summarized in Table 3.
[0048]
Ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butylene glycol, tetramethylene glycol, pentamethylene glycol having a certain boiling point as a material for the adhesive layer and having a boiling point below the fixing temperature between the substrate and the crystalline semiconductor particles, Hexylene glycol, octylene glycol, glycerin and perfluorokerosine were applied by screen printing or a doctor blade. As a comparative example, butyral resin, methylcellulose, ethylcellulose, polyvinyl alcohol (PVA) dissolved in an organic solvent as an organic resin material that does not have a boiling point as an adhesive layer material and decomposes and volatilizes in an oxygen atmosphere. Was used.
[0049]
[Table 3]

[0050]
All samples were able to adhere p-type silicon particles on the substrate with a projected area ratio of 70% or more before fixing.
[0051]
However, in Comparative Examples 5, 6, and 7, there were those in which the silicon particles could not be fixed to the substrate in the state after fixing, and the projected area ratio of the p-type silicon particles was low.
[0052]
This is because the material of the adhesive layer does not have a boiling point and decomposes and volatilizes in an oxygen atmosphere, so the material of the adhesive layer remains at the temperature at the time of fixing, and the aluminum alloy of the substrate It is considered that a residual film was formed on the surface and the formation of a eutectic of aluminum and silicon particles on the substrate was hindered.
[0053]
On the other hand, in Examples 23 to 42, even when the particle diameter of the silicon particles was 0.2 mm or 0.6 mm, the projected area ratio of the p-type silicon particles was able to maintain the state before fixing. This is because it becomes possible to fix the silicon particles tightly by using an adhesive layer having a certain degree of viscosity, and to evaporate below the temperature at the time of fixing and leave no remaining components, so that the aluminum of the substrate This is probably because the eutectic of silicon particles was formed well.
[0054]
From the above, it has been confirmed that according to the method for manufacturing a photoelectric conversion device of the present invention, it is possible to manufacture a photoelectric conversion device capable of arranging silicon particles on a substrate with a high projected area ratio.
[0055]
【The invention's effect】
As described above, according to the method for manufacturing a photoelectric conversion device of the present invention, a large number of non-uniform crystal semiconductor particles with the adhesive applied to the substrate surface and the substrate applied adhesive side as the lower surface in by pulling the substrate after pressing, dropped excess crystal semiconductor particles with temporarily adhering the crystal semiconductor particles on a substrate, subjected thereafter the load on the crystal semiconductor particles substrate eutectic temperature of the crystal semiconductor particles fixed the crystal semiconductor particles to the substrate after being or volatilization while volatilizing the adhesive by heating above, further dislodge the crystal semiconductor particles not fixed to the substrate, the particle size on the substrate not by applying a uniform crystal semiconductor particles by mixing the adhesive paste, crystal semiconductor particles temporarily adhered to the substrate, then load crystalline semiconductor particles Over and secured to the crystal semiconductor particles to the substrate after being or volatilization while volatilizing the adhesive by heating in the substrate and above the eutectic temperature of the crystal semiconductor particles, crystal semiconductor particles further not fixed to the substrate from removing, it is possible to provide a photoelectric conversion device which can be can be arranged at a high density crystal semiconductor particles on the upper surface of the substrate, thus maintaining a high conversion efficiency.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a photoelectric conversion device manufactured by the method of the present invention.
FIG. 2 is a cross-sectional view showing a conventional photoelectric conversion device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... substrate 1 '... aluminum layer 2 ... first conductivity type crystalline semiconductor particle 3 ... insulator layer 4 ... second conductivity type semiconductor layer (the other electrode layer) )
5... Protective layer 6... Adhesive layer 7... Alloy layer 8 of substrate and crystalline semiconductor particles 8.

Claims

In a method for manufacturing a photoelectric conversion device, in which a crystalline semiconductor particle exhibiting one conductivity type is disposed and fixed on a substrate and a semiconductor layer exhibiting another conductivity type is formed on the crystal semiconductor particle, an adhesive is applied to the surface of the substrate. After the substrate is applied, the side of the substrate to which the adhesive is applied is the bottom surface, and the substrate is pressed against the crystalline semiconductor particles having a non-uniform particle size. While temporarily adhering, the excess crystal semiconductor particles were dropped , and then the adhesive was volatilized or volatilized by applying a load on the crystal semiconductor particles and heating at or above the eutectic temperature of the substrate and the crystal semiconductor particles. Made in the photoelectric conversion device, wherein the substrate is fixed to the crystal semiconductor particles, further removing the crystal semiconductor particles not fixed on the substrate after Method.

Fixing a crystal semiconductor particles exhibiting one conductivity type on a substrate by disposing, in the manufacturing method of this crystal semiconductor particles photoelectric conversion device for forming a semiconductor layer exhibiting other conductivity type on the particle size on the substrate by but applying a paste obtained by mixing an adhesive agent and said crystalline semiconductor particles of non-uniform, the crystalline semiconductor particles temporarily adhered to the substrate, the substrate and the crystal semiconductor subsequent load subjected on the crystal semiconductor particles The crystal semiconductor particles are fixed to the substrate while the adhesive is volatilized or volatilized by heating at a temperature equal to or higher than the eutectic temperature of the particles, and the crystal semiconductor particles that are not fixed to the substrate are further removed . A method for manufacturing a photoelectric conversion device.

After temporarily bonding said crystalline semiconductor particles on the substrate, method of manufacturing the photoelectric conversion device according to claim 1 or 2, characterized in that pressing with a roller.

4. The adhesive according to claim 1, wherein the adhesive is made of an organic resin material burned off at a temperature lower than the eutectic temperature by 250 ° C. to a eutectic temperature, and is heated in an oxygen-containing atmosphere. A method for manufacturing a photoelectric conversion device.

5. The method for manufacturing a photoelectric conversion device according to claim 4, wherein the organic resin material is one or more of butyral resin, methyl cellulose, ethyl cellulose, polyvinyl alcohol (PVA), and polyethylene glycol (PEG). .

4. The photoelectric conversion according to claim 1, wherein the adhesive is made of an organic material having a boiling point equal to or lower than a fixing temperature between the substrate and the crystalline semiconductor particles, and is heated in an inert atmosphere. Device manufacturing method.

The organic material is one or more of ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butylene glycol, tetramethylene glycol, pentamethylene glycol, hexylene glycol, octylene glycol, glycerin, and perfluorokerosine. The process for producing a photoelectric conversion device according to claim 6, comprising:

4. The method for manufacturing a photoelectric conversion device according to claim 1, wherein the crystal semiconductor particles are disposed at a density of 70% or more in terms of a projected area ratio from the upper surface of the substrate.

4. The method for manufacturing a photoelectric conversion device according to claim 1, wherein the substrate is made of aluminum, and the crystalline semiconductor particles are made of silicon.

The method for manufacturing a photoelectric conversion device according to claim 1, wherein an average particle size of the crystalline semiconductor particles is 0.2 to 0.6 mm.