JPH03218684A - Solar cell element and manufacture thereof - Google Patents
Solar cell element and manufacture thereofInfo
- Publication number
- JPH03218684A JPH03218684A JP2012606A JP1260690A JPH03218684A JP H03218684 A JPH03218684 A JP H03218684A JP 2012606 A JP2012606 A JP 2012606A JP 1260690 A JP1260690 A JP 1260690A JP H03218684 A JPH03218684 A JP H03218684A
- Authority
- JP
- Japan
- Prior art keywords
- light
- receiving surface
- conductive layer
- solar cell
- substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 239000000758 substrate Substances 0.000 claims abstract description 50
- 238000000034 method Methods 0.000 claims abstract description 8
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 17
- 229910052710 silicon Inorganic materials 0.000 claims description 17
- 239000010703 silicon Substances 0.000 claims description 17
- 238000005530 etching Methods 0.000 claims description 10
- 239000000126 substance Substances 0.000 claims description 7
- 239000012670 alkaline solution Substances 0.000 claims description 5
- 238000007650 screen-printing Methods 0.000 claims description 5
- JVJQPDTXIALXOG-UHFFFAOYSA-N nitryl fluoride Chemical compound [O-][N+](F)=O JVJQPDTXIALXOG-UHFFFAOYSA-N 0.000 claims description 3
- 238000004140 cleaning Methods 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 238000007639 printing Methods 0.000 abstract description 3
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000000206 photolithography Methods 0.000 description 2
- 229910000676 Si alloy Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- QZPSXPBJTPJTSZ-UHFFFAOYSA-N aqua regia Chemical compound Cl.O[N+]([O-])=O QZPSXPBJTPJTSZ-UHFFFAOYSA-N 0.000 description 1
- 229910021419 crystalline silicon Inorganic materials 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は結晶シリコン太陽電池に係り、特に，表面反射
，集電抵杭の低減に配慮した太陽電池素子に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a crystalline silicon solar cell, and particularly to a solar cell element that takes into account surface reflection and reduction of current collection resistance.
太陽電池素子の効率を高めるため、素子の表面反射によ
る光エネルギー損失の低減、素子内での集電抵杭の損失
の低減が図られている。表面反射の低減に関しては、単
結晶太陽電池では公知のアルカリ溶液によるシリコンの
面方位によるエッチ速度のちがいを利用した（１ ０
０）面上へのピラミッド形成（テクスチャーエッチング
）や■溝形成が行われている（例えば特開昭６１− ２
０６２７２号公報）。In order to increase the efficiency of solar cell elements, attempts are being made to reduce optical energy loss due to surface reflection of the element and loss of current collecting resistors within the element. Regarding the reduction of surface reflection, we utilized the difference in etch rate depending on the plane orientation of silicon using a well-known alkaline solution for single-crystal solar cells (10
0) Pyramid formation (texture etching) and groove formation on the surface (for example, JP-A-61-2)
06272).
集電抵抗損失の増加を防ぐには、電極線幅を細くして多
数形成することが必要であり，高価なホトリソグラフィ
ー等の技術を要していた。In order to prevent an increase in current collection resistance loss, it is necessary to form a large number of electrodes with narrower line widths, which requires expensive techniques such as photolithography.
多結晶シリコン太陽電池は低コストであるが、結晶方位
がランダムのため、前述のアルカリ溶液によるシリコン
の面方位エッチ速度の違いを利用したテクスチャーエッ
チングが不完全となるため、光の表面反射を低減するこ
とが困難であった。Polycrystalline silicon solar cells are low cost, but because the crystal orientation is random, the texture etching that takes advantage of the difference in the etching speed of the silicon surface orientation by the alkaline solution described above is incomplete, which reduces surface reflection of light. It was difficult to do so.
また、素子内の電極線幅を細くして多数形成することは
、高価なホトリソグラフイー技術を必要としていた。Furthermore, forming a large number of thin electrode lines within an element requires expensive photolithography technology.
本発明の課題は、多結晶シリコン太陽電池表面の光の反
射を低減し、かつ電池内の集電抵抗を低，威させるにあ
る６
〔課題を解決するための手段〕
上記の課題は、基板上に形成された受光面導電層と，該
受光面導電層に接して形成され発生する電流を集電する
受光面電極と，を備えた太陽電池素子において、前記基
板の受光面に多数の凹みが設けられ、前記受光面導電層
が該凹みの面を覆って形成されることにより達成される
。An object of the present invention is to reduce the reflection of light on the surface of a polycrystalline silicon solar cell and to reduce the current collection resistance within the cell. In a solar cell element comprising a light-receiving surface conductive layer formed on the light-receiving surface conductive layer and a light-receiving surface electrode formed in contact with the light-receiving surface conductive layer to collect the generated current, the light-receiving surface of the substrate has a large number of depressions. is provided, and the light-receiving surface conductive layer is formed to cover the surface of the recess.
上記凹みは、基板の受光面に形成された、互いに平行な
複数の溝であってもよいし、基板の受光面に形成された
、互いに接する複数の穴であってもよい。The recesses may be a plurality of grooves parallel to each other formed on the light receiving surface of the substrate, or may be a plurality of holes formed in the light receiving surface of the substrate and in contact with each other.
また、基板の受光面に互いに平行な複数の溝が形成され
、受光面電極は前記基板の受光面に前記複数の溝に交叉
する方向に設けられた溝に形成されている、請求項２に
記載の太陽電池素子としてもよい。Further, according to claim 2, a plurality of grooves parallel to each other are formed on the light-receiving surface of the substrate, and the light-receiving surface electrode is formed in a groove provided in the light-receiving surface of the substrate in a direction intersecting the plurality of grooves. It may also be used as the solar cell element described above.
また、基板上に形成された受光面導電層と、該受光面導
電層に接して形成され発生する電流を集電する受光面電
極と、前記基板の前記受光面導電層が形成されている面
の反対側の面に形成された裏面導電層と、該裏面導電層
に接して形成された裏面電極と、を備えた太陽電池素子
において、前記基板の受光面及び裏面に多数の凹みが設
けられ，前記受光面導電層及び前記裏面導電層は該多数
の凹みをおおって形成されている太陽電池素子によって
も達成される。Further, a light-receiving surface conductive layer formed on the substrate, a light-receiving surface electrode formed in contact with the light-receiving surface conductive layer and collecting a generated current, and a surface of the substrate on which the light-receiving surface conductive layer is formed. In a solar cell element comprising a back conductive layer formed on the opposite surface of the substrate and a back electrode formed in contact with the back conductive layer, a large number of recesses are provided on the light-receiving surface and the back surface of the substrate. , the light-receiving surface conductive layer and the back surface conductive layer are also achieved by a solar cell element formed covering the plurality of recesses.
また、受光面導電層及び裏面導電層に設けられた凹みが
，互いに平行な複数の溝である請求項５に記載の太陽電
池素子としてもよい。Further, the solar cell element according to claim 5, wherein the recesses provided in the light-receiving surface conductive layer and the back surface conductive layer are a plurality of grooves parallel to each other.
受光面導電層側の溝の位置と、これに対応する裏面導電
層側の溝の位置が異なっている請求項６に記載の太陽電
池素子としてもよい。The solar cell element according to claim 6, wherein the position of the groove on the light-receiving surface conductive layer side is different from the position of the corresponding groove on the back surface conductive layer side.
さらに、請求項１乃至７に記載の太陽電池素子を備えた
太陽電池としてもよい。Furthermore, it may be a solar cell equipped with the solar cell element according to any one of claims 1 to 7.
また、前記の課題は、平行な２面を有するシリコン基板
の一方の面に酎薬品性のレジストをスクリーン印刷する
手順と、前記シリコン基板の該耐薬品性のレジストが印
刷された面を弗硝酸エッチングして該基板面に溝を形成
する手順と、弗硝酸エソチング終了後に前記シリコン基
板から前記レシストを洗浄除去する手順と、レジストが
除去された前記シリコン基板全体をアルカリ溶液によっ
てテクスチャーエッチングする手順と、前記シリコン基
板の溝が形成されている側の面に、導電層を形成する手
順と、を備えた太陽電池素子の製造方法によっても達成
される。In addition, the above-mentioned problem was solved by a procedure for screen printing a chemical-resistant resist on one side of a silicon substrate having two parallel sides, and a procedure for screen-printing a chemical-resistant resist on one side of the silicon substrate, and a process for screen-printing a chemical-resistant resist on the side of the silicon substrate on which the chemical-resistant resist was printed. A step of etching to form a groove on the surface of the substrate, a step of cleaning and removing the resist from the silicon substrate after the completion of fluoro-nitric acid etching, and a step of texture etching the entire silicon substrate from which the resist has been removed using an alkaline solution. The present invention can also be achieved by a method for manufacturing a solar cell element comprising the steps of: forming a conductive layer on the surface of the silicon substrate on which the groove is formed.
受光面の凹みに照射された光は、その一部が素子内に入
射し、一部は反射される。反射された光はさらに凹みの
側壁面に当ってその一部がまた、素子内に入射される。Part of the light irradiated into the recess of the light-receiving surface enters the element, and part of it is reflected. The reflected light further hits the side wall surface of the recess and a portion of it also enters the element.
順次、このような動作が繰り返されるため、素子受光面
に照射された光が実質的に素子外に反射される量がすく
なくなる。Since such operations are repeated one after another, the amount of light irradiated onto the element light-receiving surface that is reflected outside the element is substantially reduced.
また、凹み壁面に形成される導電層により全体としての
、導電層断面積が増加し、熱電抵抗が低減する。太陽電
池においては、導電層中のｎ十濃度をひくくシてオージ
ェー（ＡＵＧＥＲ）効果によるライフタイムの低下を防
止することが必要であるため、通常ｎ十層である導電層
のシート抵抗が高くなるのが避けられず、この層の抵抗
が集電抵杭の大部分を占めており，この導電層の抵抗の
低減は太陽電池全体の集電抵杭の低減に大きく影響する
。In addition, the conductive layer formed on the wall surface of the recess increases the overall cross-sectional area of the conductive layer and reduces thermoelectric resistance. In solar cells, it is necessary to reduce the n+ concentration in the conductive layer to prevent a decrease in lifetime due to the Auger effect, so the sheet resistance of the conductive layer, which is usually an n+ layer, increases. This is unavoidable, and the resistance of this layer accounts for most of the current collector resistance pile, and reducing the resistance of this conductive layer has a large effect on reducing the collector resistance pile of the entire solar cell.
受光面に形成される凹みが、受光面電極に交叉する方向
に形成された溝であれば、受光面電極に向かう方向の電
流の流路断面積が増加し、特にその方向での集電抵杭の
低減に効果的である。If the recess formed on the light-receiving surface is a groove formed in the direction that intersects the light-receiving surface electrode, the cross-sectional area of the current flow in the direction toward the light-receiving surface electrode increases, and the current collector resistor in that direction increases. Effective in reducing piles.
以下、本発明の一実施例を第１図〜第４図により説明す
る。太陽電池素子１は、Ｐ型多結晶シリコン基板である
キャスト基板１１と、該キャスト基板１１の受光面側の
面上に該面をおおって形成された受光面ｎ十型導電層３
と、該受光面導電層に平行線状に形成された受光面電極
と、を備えている。キャスト基板１１の受光面側と反対
側の面（以下裏面という）には、その面をおおって裏面
Ｐ十型導電層４が形成され、該裏面導電層４上には、更
にＡｇ電極である裏面電極５が形成されている。キャス
ト基板１１は、厚さがほぼ４００μｍで、比抵抗がほぼ
１．０Ω／ｍであり、受光面導電層３は，厚さがほぼ０
．３μｍ、シート抵抗がほぼ７ｏΩ／口である。キャス
ト基板１１の受光面側の面には、深さがほぼ５０μｍ、
幅がほぼ１００μｍの直線状の溝２１がほぼ１００μｍ
の間隔で、平行に多数、形成されている。また５前記溝
２１と同じ深さ、幅の直線状の溝２２が、溝２１と直交
する方向に、均一な間隔をおいて、多数形成されている
。前記受光面導電層３は、溝２１．２２の底面，側面に
も、同様な厚さ（ほぼ、０．３μｍ）で形成されている
。また、溝２２内にはＡｇペーストの印刷及び焼成によ
り、前記受光面電極の一部をなす受光面フィンガー電極
６１がほぼ溝を充填するように形成されており、所定の
間隔をおいて選定された溝２１にも、前記受光面フィン
ガー電極６１と同様にして同じく、前記受光面電極の一
部をなす受光面バスバー電極６２が形成されている。受
光面バスバー電極６２と受光面フィンガー電極６１とは
、その交叉位置で電気的に接続されており、受光面バス
バー電極６２が幹とすれば、受光面フィンガー電Ｖｉ６
１は幹に対する枝の関係にある。An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. The solar cell element 1 includes a cast substrate 11 which is a P-type polycrystalline silicon substrate, and a light-receiving surface n-type conductive layer 3 formed on the light-receiving surface side of the cast substrate 11 and covering the surface.
and a light-receiving surface electrode formed in a parallel line shape to the light-receiving surface conductive layer. On the surface of the cast substrate 11 opposite to the light-receiving surface side (hereinafter referred to as the back surface), a back P-shaped conductive layer 4 is formed to cover the surface, and on the back conductive layer 4, an Ag electrode is further formed. A back electrode 5 is formed. The cast substrate 11 has a thickness of approximately 400 μm and a specific resistance of approximately 1.0 Ω/m, and the light-receiving surface conductive layer 3 has a thickness of approximately 0 μm.
．． 3 μm, and the sheet resistance is approximately 7 oΩ/hole. The surface of the cast substrate 11 on the light-receiving surface side has a depth of approximately 50 μm;
The linear groove 21 with a width of approximately 100 μm is approximately 100 μm.
They are formed in large numbers in parallel at intervals of . Further, a large number of linear grooves 22 having the same depth and width as the grooves 21 are formed in a direction perpendicular to the grooves 21 at uniform intervals. The light-receiving surface conductive layer 3 is also formed on the bottom and side surfaces of the grooves 21 and 22 with a similar thickness (approximately 0.3 μm). Further, within the groove 22, light-receiving surface finger electrodes 61, which form part of the light-receiving surface electrode, are formed by printing and baking Ag paste so as to almost fill the groove, and are selected at predetermined intervals. Similarly to the light-receiving surface finger electrode 61, a light-receiving surface bus bar electrode 62, which forms a part of the light-receiving surface electrode, is also formed in the groove 21. The light-receiving surface busbar electrode 62 and the light-receiving surface finger electrode 61 are electrically connected at their intersection position, and if the light-receiving surface busbar electrode 62 is the trunk, the light-receiving surface finger electrode Vi6
1 is in the relationship of branches to the trunk.
このような構造では、太陽電池の集電抵杭の最も大きな
割合を占めている。ｎ十型導電層３から受光面フィンガ
ー電極６１までの間の集電抵抗が小さくなる。すなわち
、ｎ十型導電層の受光面フィンガー電極６１の長手方向
に平行な面での断面積が、溝２１がない場合に比べて、
ほぼ、１．５倍となっているので，集電抵抗は１７１．
５ となる。このことはまた、溝２１がある場合のｎ
十型導電層３のシート抵抗７０Ω／口が、溝がない場合
のシート抵抗５０Ω／口に相当することを意味する。ｎ
十型導電層３のシート抵抗５０Ω／口，受光面フィンガ
ー電極線幅１００μｍに対する最適な受光面フィンガー
間隔は３ｍｍであり、溝２２の間隔、すなわち受光面フ
ィンガー電極６１の間隔は３ｍｍとしてある。このＰ型
多結晶シリコン基板１１の裏面に形成された裏面導電層
４は、Ｐ＋型導電層であり、そのシート抵抗はほぼ３０
Ω／口、厚さほぼ７μｍである。This structure accounts for the largest proportion of current collector piles in solar cells. The current collection resistance between the n-type conductive layer 3 and the light-receiving surface finger electrode 61 is reduced. That is, the cross-sectional area of the light-receiving surface finger electrode 61 of the n-type conductive layer in a plane parallel to the longitudinal direction is smaller than that in the case where there is no groove 21.
Since it is approximately 1.5 times as large, the current collecting resistance is 171.
It becomes 5. This also means that when there is a groove 21, n
This means that the sheet resistance of the ten-shaped conductive layer 3 of 70Ω/portion corresponds to the sheet resistance of 50Ω/portion when there is no groove. n
The optimum distance between the light receiving surface fingers is 3 mm for the sheet resistance of the ten-shaped conductive layer 3 of 50 Ω/hole and the line width of the light receiving surface finger electrodes of 100 μm, and the distance between the grooves 22, that is, the distance between the light receiving surface finger electrodes 61 is 3 mm. The back conductive layer 4 formed on the back surface of this P-type polycrystalline silicon substrate 11 is a P+ type conductive layer, and its sheet resistance is approximately 30.
Ω/hole, thickness approximately 7 μm.
上述の構成の太陽電池素子において、溝２１の溝底面に
当った光は、一部素子内に入射し，一部は反射されるが
反射された光のさらに一部は、溝２１の側面に当る。該
側面に当った光は一部が素子内に入射し一部が反射され
る，順次、このような入射，反射が繰り返されるので、
溝２１に入射した光は平坦部（溝でない部分）に入射し
た光に比べ、最終的に素子外に反射される光の量が少な
いので、，光から電気への変換効率が向上する。In the solar cell element having the above configuration, a portion of the light that hits the groove bottom surface of the groove 21 enters the element, and a portion of the light is reflected, but a further portion of the reflected light is reflected on the side surface of the groove 21. Hit. Part of the light that hits the side surface enters the element and part of it is reflected, and this type of incidence and reflection is repeated in sequence, so
The amount of light that is incident on the groove 21 is ultimately reflected outside the element compared to the light that is incident on a flat portion (a portion that is not a groove), so that the conversion efficiency from light to electricity is improved.
本実施例においては溝の深さをほぼ５０μｍ，溝幅をほ
ぼ１００μｍとしたが，溝幅をせまくし溝深さを深くし
て溝の壁面部分をふやすほど、変換効率の向上に有効で
ある。In this example, the depth of the groove was approximately 50 μm and the width of the groove was approximately 100 μm, but the narrower the groove width and the deeper the groove depth to increase the wall surface of the groove, the more effective it is in improving the conversion efficiency. .
ｎ十型導電層３は、そのシート抵抗が７ｏΩ／口と高い
ことから分るように、不純物濃度が低いこのためオージ
ェー（Ａｕｇｅｒ）効果によるｎ十型導電層の少数キャ
リアライフタイムの低下が少なく光生成電流のｎ十型導
電層における再結合損失が少ない。このため、高い変換
効率が得られる。また５ｎ十型導電層のシート抵抗は理
想的には１５０Ω／口程度、すなわち，シート抵抗が１
５０Ω／口程度になるような不純物濃度であることが望
ましいが、そうするためには、溝２２，受光面フィンガ
ー電極６ｌの幅を狭くして本数を増やし，がつ溝２２お
よび受光面フィンガー電極６１の深さを深くする必要が
ある。The n-type conductive layer 3 has a low impurity concentration, as can be seen from its high sheet resistance of 7 ohm/min, so that the minority carrier lifetime of the n-type conductive layer 3 is less likely to decrease due to the Auger effect. Recombination loss of photogenerated current in the n-type conductive layer is small. Therefore, high conversion efficiency can be obtained. In addition, the sheet resistance of the 5n 10-type conductive layer is ideally about 150Ω/hole, that is, the sheet resistance is 1
It is desirable that the impurity concentration is about 50 Ω/hole, but in order to do so, the width of the groove 22 and the light-receiving surface finger electrode 6l should be narrowed to increase the number of grooves 22 and the light-receiving surface finger electrode 6l. It is necessary to increase the depth of 61.
また、本実施例．は、Ｐ型多結晶シリコン基板に受光面
ｎ十型導電層，裏面Ｐ十型導電層を設けたものであるが
、ｎ十型多結晶シリコン基板に、受光面Ｐ十型導電層，
裏面ｎ十型導電層を設けてもよい。Also, this example. In this example, a P-type polycrystalline silicon substrate is provided with an n-type conductive layer on the light-receiving surface and a P-type conductive layer on the back surface.
A backside n-type conductive layer may be provided.
本実施例の製造方法を次に説明する。まず、Ｐ型多結晶
シリコン基板１１の受光面に、耐薬品性のレジストが、
スクリーン印刷される。このとき互いに直交する２方向
の溝となる部分以外の部分にレジストが付着されるよう
に印刷される。このときのレジストとレジストの最小間
隔は、スクリーン印刷では、ほぼ５０μｍが最小限界で
あり，前述の実施例においてはレジストの間隔として、
この数値が採用された。次にスクリーン印刷された面に
弗硝酸エッチングが行われ、シリコン基板受光而の前記
レジストでおおわれていない部分に、深さがほぼ５０μ
ｍ．幅がほぼ７０μｍの溝が形成される。次に前記印刷
されたレジストが洗浄，除去される。次いでシリコン基
板全体に対してアルカリ溶液によるテクスチャーエッチ
ングが行われ、溝深さほぼ５０μｍ、溝幅ほぼ１００μ
ｍの溝が形成される。次に拡散法により、受光面にシー
ト抵抗がほぼ７０Ω／口、厚みがほぼ０．３μｍのｎ十
型導電層（受光面導電層）３が形成される。次にシリコ
ン基板の裏面全面にアルミニウムペーストが印刷され、
これが焼成されて、裏面Ｐ十型導電層４およびＡＱ−Ｓ
ｉ合金層が形成される。次に前記ＡＱ−Ｓｉ合金層が王
水により除去され、除去面にＡｇペーストが印刷・焼成
されてＡｇ電極である裏面電極が形成される。次に受光
面に形成された溝のうちの、間隔３■ごとに形成された
溝および、これに直交する溝の一部にＡｇペーストが印
刷され、焼成されて、受光面フィンガー電極６１および
受光面バスバー電極６２が形成される。このようにして
製造された太陽電池素子が通常複数個組み合わされ，電
力を取り出すターミナルが設けられて太陽電池となる。The manufacturing method of this example will be explained below. First, a chemical-resistant resist is applied to the light-receiving surface of the P-type polycrystalline silicon substrate 11.
Screen printed. At this time, printing is performed so that the resist is adhered to the portions other than the portions forming the grooves in two directions perpendicular to each other. The minimum distance between the resists at this time is approximately 50 μm in screen printing, and in the above example, the distance between the resists is as follows:
This value was adopted. The screen-printed surface is then etched with hydrofluoric acid to a depth of approximately 50 μm on the portions of the silicon substrate that are not covered with the resist.
m. A groove with a width of approximately 70 μm is formed. Next, the printed resist is washed and removed. Next, texture etching is performed on the entire silicon substrate using an alkaline solution, and the groove depth is approximately 50 μm and the groove width is approximately 100 μm.
m grooves are formed. Next, an n0-type conductive layer (light-receiving surface conductive layer) 3 having a sheet resistance of approximately 70 Ω/hole and a thickness of approximately 0.3 μm is formed on the light-receiving surface by a diffusion method. Next, aluminum paste is printed on the entire back side of the silicon substrate.
This is fired to form the back P ten-shaped conductive layer 4 and the AQ-S
An i-alloy layer is formed. Next, the AQ-Si alloy layer is removed using aqua regia, and an Ag paste is printed and fired on the removed surface to form a back electrode which is an Ag electrode. Next, among the grooves formed on the light-receiving surface, Ag paste is printed on the grooves formed at intervals of 3 cm and a part of the grooves perpendicular to these, and is fired to form the light-receiving surface finger electrode 61 and the light-receiving surface. A planar busbar electrode 62 is formed. A plurality of solar cell elements manufactured in this manner are usually assembled together and provided with a terminal for extracting electric power to form a solar cell.
このようにして製作された太陽電池の表面の反射は，テ
クスチャーエッチングされた多結晶シリコン基板を用い
た太陽電池に比べほぼ５０％に低減された。また集電抵
抗は従来の溝なしのシート抵抗７０Ω／口に対して、ほ
ぼ７０％に低減された。また、変換効率は、従来の太陽
電池に比べほぼその１５％向上した。The surface reflection of the solar cell fabricated in this way was reduced by approximately 50% compared to a solar cell using a texture-etched polycrystalline silicon substrate. Furthermore, the current collection resistance was reduced to approximately 70% compared to the conventional sheet resistance without grooves of 70Ω/hole. Furthermore, the conversion efficiency was improved by approximately 15% compared to conventional solar cells.
次に、本発明の第２の実施例を第５図〜第８図により説
明する。第２の実施例は、本発明を太陽電池素子の受光
面及び裏面に適用したもので，本実施例の太陽電池素子
は多結晶シリコン基板１１の受光面に先の実施例を同様
の構造（溝２１，２２，受光面導電層３，溝内に形成さ
れ，互いに直交する受光面フィンガー電極６１，受光面
バス／＜−６２）を備え，裏面に、受光面側の溝２１と
平行な溝２３及び溝２２と平行な溝２４が多数形成され
ている。溝２３と溝２４の深さはほぼ等しく，その幅も
ほぼ等しい。溝２３の間隔は溝２２の間隔と同しくほぼ
１００μｍである。前記シリコン基板１の裏面には、前
記溝２３．２４の底面側面を含めて、裏面導電層４が全
面に形成されており、溝２４内には裏面フィンガー電極
５１が受光面側の電極と同様の方法で形成されている。Next, a second embodiment of the present invention will be described with reference to FIGS. 5 to 8. In the second embodiment, the present invention is applied to the light-receiving surface and the back surface of a solar cell element, and the solar cell element of this embodiment has a similar structure ( Grooves 21 and 22, a light-receiving surface conductive layer 3, light-receiving surface finger electrodes 61 formed in the grooves and perpendicular to each other, and a light-receiving surface bus (<-62), and a groove parallel to the light-receiving surface side groove 21 on the back surface. 23 and a large number of grooves 24 parallel to the grooves 22 are formed. The depths of the grooves 23 and the grooves 24 are approximately equal, and their widths are also approximately equal. The interval between the grooves 23 is the same as the interval between the grooves 22, and is approximately 100 μm. A back conductive layer 4 is formed on the entire back surface of the silicon substrate 1, including the bottom side surfaces of the grooves 23 and 24, and a back finger electrode 51 is provided in the groove 24 in the same manner as the electrode on the light receiving surface side. It is formed by the following method.
また、裏面フィンガー電極５１と直交する溝２３のいく
つかには、裏面バスバー電極５２が形成され前記裏面フ
ィンガー電極５１と電気的に接続されている。溝２４の
間隔は、集電抵抗を小さくするには狭くした方が良いが
、狭くすると電極を形成するＡｇペーストの費用が嵩む
。本実施例においては、溝２４の側壁面による導電層の
断面増加による集電抵抗低下を考慮して、溝２４の間隔
を１ｍとし、従来の全面に形成された裏面電極に比べ、
材料費の低減が可能となった。また、受光面の溝２１．
２２の形成位置と、裏面の溝２３．２４の形成位置をず
らすことにより溝部でのシリコン基板の厚みの減少を少
なくし、素子製作時の割れを少なくできた。Furthermore, back bus bar electrodes 52 are formed in some of the grooves 23 orthogonal to the back finger electrodes 51 and are electrically connected to the back finger electrodes 51 . It is better to make the interval between the grooves 24 narrower in order to reduce the current collecting resistance, but if the interval is narrower, the cost of Ag paste for forming the electrodes will increase. In this embodiment, in consideration of the reduction in current collecting resistance due to the increase in the cross section of the conductive layer due to the sidewall surface of the grooves 24, the interval between the grooves 24 is set to 1 m, and compared to the conventional back electrode formed on the entire surface,
It has become possible to reduce material costs. Further, the groove 21 on the light receiving surface.
By shifting the formation position of 22 from the formation position of the grooves 23 and 24 on the back surface, it was possible to reduce the decrease in the thickness of the silicon substrate at the groove part, and to reduce cracks during device fabrication.
第９図は、本発明の第３の実施例を示し、受光面に形成
される溝２１が，直線状でなく、たがいに平行な曲線状
をなしている例である．本実施例によれば、光線の入射
方向が溝２１の方向と一致することがなく，入射方向に
よる反射率の差が低減される。FIG. 9 shows a third embodiment of the present invention, in which the grooves 21 formed on the light-receiving surface are not linear but curved parallel to each other. According to this embodiment, the incident direction of the light beam does not coincide with the direction of the groove 21, and the difference in reflectance depending on the incident direction is reduced.
第１０図は本発明の第４実施例を示し，受光面に溝２１
のかわりに多数のたがいに接する穴状のくぼみ２１Ａが
設けられている。本実施例によれば、光の入射方向によ
る差がさらに少なくなるとともに、受光面導電層の断面
積も増加し、集電抵抗低下の効果がある。FIG. 10 shows a fourth embodiment of the present invention, in which grooves 21 are formed on the light receiving surface.
Instead, a large number of hole-shaped depressions 21A are provided that touch each other. According to this embodiment, the difference depending on the incident direction of light is further reduced, and the cross-sectional area of the light-receiving surface conductive layer is also increased, which has the effect of lowering the current collection resistance.
本発明によれば、太陽電池素子の受光面に多数のくぼみ
が形成され、受光面導電層が該くぼみの面をおおって形
成されているので、入射した光の反射が少なくなるとと
もに，素子内の集電抵抗が低減され、変換効率が向上す
る効果がある。According to the present invention, a large number of depressions are formed on the light-receiving surface of a solar cell element, and the light-receiving surface conductive layer is formed to cover the surface of the depressions, so that reflection of incident light is reduced and the inside of the element is reduced. This has the effect of reducing current collection resistance and improving conversion efficiency.
第１図は本発明の第１の実施例である太陽電池素子の受
光面を示す平面図、第２図は第１図のＡ部詳細を示す平
面図、第３図は第２図の■一■線矢視断面図、第４図は
第２図のｒＶ−ｒＶ線矢視断面図、第５図は本発明の第
２の実施例である太陽電池素子の裏面を示す平面図、第
６図は第５図のＡ部詳細を示す平面図、第７図は第６図
の■−■線矢視断面図、第８図は第６図の■−■線矢視
断面図、第９図は本発明の第３の実施例を示す斜視図で
，第１０図は本発明の第４の実施例を示す斜視図である
。
１・・・太陽電池素子、３・・受光面導電層、４・・・
裏面導電層、５・・裏面電極、１１・・・基板（多結晶
シリコン基板）．２１，２２，２３．２４・・・凹み（
溝）２１Ａ・・・凹み（穴）．５１．５２・・・裏面電
極、６１・・・受光面電極（受光面フィンガー電極）、
６２・・受光面電極（受光面バスバー電極）。FIG. 1 is a plan view showing the light-receiving surface of a solar cell element according to the first embodiment of the present invention, FIG. 2 is a plan view showing details of section A in FIG. 1, and FIG. 4 is a sectional view taken along the line rV-rV in FIG. 2; FIG. Fig. 6 is a plan view showing details of part A in Fig. 5, Fig. 7 is a sectional view taken along the line ■-■ in Fig. 6, and Fig. 8 is a sectional view taken along the line -■ in Fig. 6. FIG. 9 is a perspective view showing a third embodiment of the invention, and FIG. 10 is a perspective view showing a fourth embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Solar cell element, 3... Light-receiving surface conductive layer, 4...
Back conductive layer, 5... Back electrode, 11... Substrate (polycrystalline silicon substrate). 21, 22, 23, 24...dent (
groove) 21A... recess (hole). 51.52... Back electrode, 61... Light receiving surface electrode (light receiving surface finger electrode),
62... Light receiving surface electrode (light receiving surface bus bar electrode).
Claims (1)
層に接して形成され発生する電流を集電する受光面電極
と、を備えた太陽電池素子において、前記基板の受光面
に多数の凹みが設けられ、前記受光面導電層は該凹みの
面を覆って形成されていることを特徴とする太陽電池素
子。 ２、凹みが、基板の受光面に形成された、互いに平行な
複数の溝であることを特徴とする請求項１に記載の太陽
電池素子。 ３、凹みが、基板の受光面に形成された、互いに接する
複数の穴であることを特徴とする請求項１に記載の太陽
電池素子。 ４、基板の受光面に互いに平行な複数の溝が形成されて
いることと、受光面電極は前記基板の受光面に前記複数
の溝に交叉する方向に設けられた溝に形成されているこ
とと、を特徴とする請求項２に記載の太陽電池素子。 ５、基板上に形成された受光面導電層と、該受光面導電
層に接して形成され発生する電流を集電する受光面電極
と、前記基板の前記受光面導電層が形成されている面の
反対側の面に形成された裏面導電層と、該裏面導電層に
接して形成された裏面電極と、を備えた太陽電池素子に
おいて、前記基板の受光面及び裏面に多数の凹みが設け
られ、前記受光面導電層及び前記裏面導電層は該多数の
凹みをおおって形成されていることを特徴とする太陽電
池素子。 ６、受光面導電層及び裏面導電層に設けられた凹みが、
互いに平行な複数の溝であることを特徴とする請求項５
に記載の太陽電池素子。 ７、受光面導電層側の溝の位置と、これに対応する裏面
導電層側の溝の位置が異なっていることを特徴とする請
求項６に記載の太陽電池素子。 ８、請求項１乃至７に記載の太陽電池素子を備えた太陽
電池。 ９、平行な２面を有するシリコン基板の一方の面に耐薬
品性のレジストをスクリーン印刷する手順と、前記シリ
コン基板の該耐薬品性のレジストが印刷された面を弗硝
酸エッチングして該基板面に溝を形成する手順と、弗硝
酸エッチング終了後に前記シリコン基板から前記レジス
トを洗浄除去する手順と、レジストが除去された前記シ
リコン基板全体をアルカリ溶液によってテクスチャーエ
ッチングする手順と、前記シリコン基板の溝が形成され
ている側の面に、導電層を形成する手順と、を備えた太
陽電池素子の製造方法。[Scope of Claims] 1. A solar cell element comprising a light-receiving surface conductive layer formed on a substrate, and a light-receiving surface electrode formed in contact with the light-receiving surface conductive layer to collect generated current, A solar cell element characterized in that a large number of recesses are provided on the light-receiving surface of the substrate, and the light-receiving surface conductive layer is formed to cover the surface of the recesses. 2. The solar cell element according to claim 1, wherein the recesses are a plurality of mutually parallel grooves formed on the light-receiving surface of the substrate. 3. The solar cell element according to claim 1, wherein the recess is a plurality of holes formed in the light-receiving surface of the substrate and in contact with each other. 4. A plurality of grooves parallel to each other are formed on the light-receiving surface of the substrate, and the light-receiving surface electrode is formed in a groove provided in a direction intersecting the plurality of grooves on the light-receiving surface of the substrate. The solar cell element according to claim 2, characterized by: 5. A light-receiving surface conductive layer formed on a substrate, a light-receiving surface electrode formed in contact with the light-receiving surface conductive layer to collect the generated current, and a surface of the substrate on which the light-receiving surface conductive layer is formed. In a solar cell element comprising a back conductive layer formed on the opposite surface of the substrate and a back electrode formed in contact with the back conductive layer, a large number of recesses are provided on the light-receiving surface and the back surface of the substrate. . A solar cell element, wherein the light-receiving surface conductive layer and the back surface conductive layer are formed to cover the plurality of recesses. 6. The recesses provided in the light-receiving surface conductive layer and the back surface conductive layer,
Claim 5 characterized in that the grooves are a plurality of grooves parallel to each other.
The solar cell element described in . 7. The solar cell element according to claim 6, wherein the position of the groove on the light-receiving surface conductive layer side is different from the position of the corresponding groove on the back surface conductive layer side. 8. A solar cell comprising the solar cell element according to any one of claims 1 to 7. 9. A step of screen printing a chemical-resistant resist on one side of a silicon substrate having two parallel sides, and etching the side of the silicon substrate on which the chemical-resistant resist is printed with fluoro-nitric acid to remove the substrate. a step of forming grooves on the surface; a step of cleaning and removing the resist from the silicon substrate after completion of the fluoro-nitric acid etching; a step of texture etching the entire silicon substrate from which the resist has been removed using an alkaline solution; A method for manufacturing a solar cell element, comprising the steps of: forming a conductive layer on a side surface on which a groove is formed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012606A JPH0697700B2 (en) | 1990-01-24 | 1990-01-24 | Solar cell element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012606A JPH0697700B2 (en) | 1990-01-24 | 1990-01-24 | Solar cell element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03218684A true JPH03218684A (en) | 1991-09-26 |
| JPH0697700B2 JPH0697700B2 (en) | 1994-11-30 |
Family
ID=11810014
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2012606A Expired - Fee Related JPH0697700B2 (en) | 1990-01-24 | 1990-01-24 | Solar cell element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0697700B2 (en) |
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|---|---|---|---|---|
| US6084175A (en) * | 1993-05-20 | 2000-07-04 | Amoco/Enron Solar | Front contact trenches for polycrystalline photovoltaic devices and semi-conductor devices with buried contacts |
| KR100446593B1 (en) * | 1997-03-05 | 2005-07-04 | 삼성전자주식회사 | Silicon solar cell and its manufacturing method |
| JP2006286822A (en) * | 2005-03-31 | 2006-10-19 | Sanyo Electric Co Ltd | Photovoltaic element and its fabrication process |
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| JP2006286822A (en) * | 2005-03-31 | 2006-10-19 | Sanyo Electric Co Ltd | Photovoltaic element and its fabrication process |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0697700B2 (en) | 1994-11-30 |
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