JP3157865B2 - Protective film for solar cells - Google Patents
Protective film for solar cellsInfo
- Publication number
- JP3157865B2 JP3157865B2 JP26031191A JP26031191A JP3157865B2 JP 3157865 B2 JP3157865 B2 JP 3157865B2 JP 26031191 A JP26031191 A JP 26031191A JP 26031191 A JP26031191 A JP 26031191A JP 3157865 B2 JP3157865 B2 JP 3157865B2
- Authority
- JP
- Japan
- Prior art keywords
- protective film
- light
- film
- solar cell
- silicon nitride
- 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.)
- Expired - Fee Related
Links
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
- Y02E10/544—Solar cells from Group III-V materials
Landscapes
- Photovoltaic Devices (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は太陽電池の保護膜に関す
るもので、特に宇宙空間で使われる人工衛星用太陽電池
に利用されるものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective film for a solar cell, and more particularly to a solar cell for an artificial satellite used in outer space.
【0002】[0002]
【従来の技術】人工衛星の電源として搭載される宇宙用
太陽電池は単結晶シリコン、ガリウム砒素(GaA
s)、や又、シリコン基板上にGaAs膜を成長させた
GaAs/Siが用いられるが、特にGaAs材料を使
った太陽電池はシリコン太陽電池に比べて高い変換効率
をもち、素子の温度上昇に対して効率の低下がすくない
などの長所があり、将来の人工衛星用太陽電池として有
望であるとされている。2. Description of the Related Art Space solar cells mounted as power supplies for artificial satellites are made of monocrystalline silicon or gallium arsenide (GaAs).
s) Alternatively, GaAs / Si in which a GaAs film is grown on a silicon substrate is used. In particular, a solar cell using a GaAs material has a higher conversion efficiency than a silicon solar cell, and the temperature of the element increases. On the other hand, there is an advantage that the efficiency is not easily reduced, and it is considered that it is promising as a solar cell for a satellite in the future.
【0003】GaAs太陽電池はpn接合を形成した表
面にAl−GaAs層を設け、この層の表面には保護の
為に耐湿性、耐薬品性にすぐれた窒化シリコン膜が用い
られることが多い。窒化シリコン膜の堆積方法は膜厚の
均一性や膜質の再現性等の理由によりプラズマCVDに
よる方法が一般的である。In a GaAs solar cell, an Al-GaAs layer is provided on a surface on which a pn junction is formed, and a silicon nitride film having excellent moisture resistance and chemical resistance is often used for protection on the surface of this layer. A method of depositing a silicon nitride film is generally a plasma CVD method for reasons such as uniformity of film thickness and reproducibility of film quality.
【0004】[0004]
【発明が解決しようとする課題】宇宙用太陽電池が使用
される環境は苛酷であり、例えば太陽光が照射している
部分と日影の部分の温度差は数百度になり、照射される
紫外光は地上では大気中の酸素により吸収される波長2
00nm以下の成分が含まれる。この、遠紫外光は窒化
シリコン膜に光化学反応を生じさせ、膜表面が硬化収縮
し、膜の割れや、基板からの剥がれが発生する可能性が
あるために有効な対策が必要である。The environment in which a solar cell for space is used is harsh. For example, the temperature difference between a portion irradiated with sunlight and a shaded portion becomes hundreds of degrees, and ultraviolet rays to be irradiated are exposed. Light is absorbed on the ground by oxygen in the atmosphere.
A component of 00 nm or less is included. This deep ultraviolet light causes a photochemical reaction in the silicon nitride film, and the surface of the film hardens and shrinks, and the film may be cracked or peeled off from the substrate. Therefore, effective measures are required.
【0005】保護膜が割れたり剥がれたりする原因とし
て、使用中の温度差や紫外光による膜の変質が考えられ
るが、室温から400℃まで温度上昇させても保護膜の
割れや剥がれは生じていないことから、温度差が原因で
はない。表1に保護膜に用いている、プラズマCVDに
より形成した窒化シリコン膜に200nm以下および2
00nm以上の波長光を含む紫外光を照射したそれぞれ
の場合の屈折率、膜厚の変化を示す。光源は低圧水銀灯
を用いて、光強度0.66mW/cm2で、空気中で9
0分間光照射を行った。なお、屈折率と膜厚はエリプソ
メトリーにより求めた。The protective film may be cracked or peeled off due to a temperature difference during use or deterioration of the film due to ultraviolet light. However, even if the temperature is raised from room temperature to 400 ° C., the protective film is cracked or peeled off. Temperature difference is not the cause. Table 1 shows that a silicon nitride film formed by plasma CVD, which is used as a protective film, has a thickness of 200 nm or less and
Changes in refractive index and film thickness in each case of irradiation with ultraviolet light including light having a wavelength of 00 nm or more are shown. The light source is a low-pressure mercury lamp with a light intensity of 0.66 mW / cm 2 and 9 in air.
Light irradiation was performed for 0 minutes. The refractive index and the film thickness were determined by ellipsometry.
【0006】[0006]
【表1】 [Table 1]
【0007】表1から、200nm以下の波長光の照射
により、保護膜の屈折率が変化して膜厚が減少している
ことが分かる。この事実から保護膜の割れや剥がれの機
構は200nm以下の波長光が照射されるに従い保護膜
の表面では膜厚が減少するような光反応が生じて表面付
近が収縮した状態になるために大きな応力が発生し、こ
のために割れが生じたり基板と保護膜の密着力に打ち勝
って剥がれが生じたりすると考えられる。From Table 1, it can be seen that the irradiation of light having a wavelength of 200 nm or less changes the refractive index of the protective film and decreases the film thickness. From this fact, the mechanism of cracking and peeling of the protective film is large because a photoreaction such that the film thickness decreases on the surface of the protective film as the light having a wavelength of 200 nm or less is irradiated and the vicinity of the surface shrinks. It is considered that a stress is generated, which causes a crack or peels off by overcoming the adhesion between the substrate and the protective film.
【0008】[0008]
【課題を解決するための手段】保護膜の割れや剥がれを
無くすためには200nm以下の波長光が保護膜に照射
されないようにすればよい。この目的を達する方法とし
て保護膜(窒化シリコン)の表面に200nm以下の波
長光を選択的に吸収するフィルターを設ける方法が考え
られる。フィルターに要求される特性は200nm以下
の波長光を選択的にカットし、かつ他の波長域の光は吸
収しないことである。In order to prevent cracking or peeling of the protective film, light having a wavelength of 200 nm or less should not be applied to the protective film. As a method of achieving this object, a method of providing a filter for selectively absorbing light having a wavelength of 200 nm or less on the surface of the protective film (silicon nitride) is considered. The characteristics required for the filter are to selectively cut off light having a wavelength of 200 nm or less and not absorb light in other wavelength ranges.
【0009】特に本発明は太陽電池の保護膜に関するも
のであり、透過光を出来る限り減ずることのない状態に
する必要がある。このような目的に合致する材料として
有機高分子膜が挙げられる。例えば、クロロメチル化ポ
リスチレンは250〜300nm以下の波長光を吸収
し、可視領域では殆ど透過するために本目的に合う。In particular, the present invention relates to a protective film for a solar cell, and it is necessary to reduce transmitted light as much as possible. An organic polymer film is mentioned as a material meeting such a purpose. For example, chloromethylation
Polystyrene absorbs a wavelength light 2 50 to 300 nm, suit this purpose to most transparent in the visible region.
【0010】クロロメチル化ポリスチレンは遠紫外光が
照射されると塩素が脱離し架橋反応が生じるので光照射
とともにポリマーの結合がより強固になり保護膜として
適している。 [0010] Chloromethylated polystyrene has a deep ultraviolet light.
When irradiated, chlorine is desorbed and a crosslinking reaction occurs, so light irradiation
Together with the polymer bond becomes stronger and as a protective film
Are suitable.
【0011】[0011]
【作用】本発明はクロロメチル化ポリスチレンからなる
有機高分子膜を表面にもつ窒化シリコン膜を保護膜に用
いることを特徴とし、この有機高分子膜は200nm以
下の遠紫外光を含む光の入射によって生じる窒化シリコ
ン膜内部での光化学反応を抑える作用が有る。The present invention is characterized in that a silicon nitride film having an organic polymer film made of chloromethylated polystyrene on its surface is used as a protective film, and this organic polymer film emits far ultraviolet light of 200 nm or less. This has the effect of suppressing the photochemical reaction inside the silicon nitride film caused by the incident light.
【0012】宇宙空間で利用されるGaAs材料を用い
た太陽電池受光面には該波長光を含む太陽光が入射し、
保護膜として形成された窒化シリコン膜に光反応を生じ
させて、割れ、剥がれが生じることがあるが、本発明に
より該反応を抑えて信頼性の高いGaAs材料を用いた
太陽電池用保護膜を形成することができる。 Using a GaAs material used in outer space
Sunlight containing the wavelength light enters the solar cell light receiving surface,
A photoreaction may occur in the silicon nitride film formed as a protective film to cause cracking and peeling. According to the present invention, the photoreaction is suppressed by using a highly reliable GaAs material by suppressing the reaction. Protective film can be formed.
【0013】[0013]
【実施例】本発明による実施例の工程を図1に示す。4
枚の半絶縁性GaAs(ガリウム砒素)基板1にプラズ
マCVDにより、図1(a)に示すように、窒化シリコ
ンを500Åの厚さになるように堆積し窒化シリコン膜
2を形成した。堆積条件は基板温度250℃、Si
H4:NH3:N2の流量比が10:110:50(SC
CM)で反応室の圧力は0.75torrであった。プ
ラズマCVDのRF周波数は13.56MHzでパワー
密度は0.45W/cm2で行った。FIG. 1 shows the steps of an embodiment according to the present invention. 4
As shown in FIG. 1A, a silicon nitride film 2 was formed on a single semi-insulating GaAs (gallium arsenide) substrate 1 by plasma CVD so as to have a thickness of 500 °. The deposition conditions were a substrate temperature of 250 ° C., Si
The flow ratio of H 4 : NH 3 : N 2 is 10: 110: 50 (SC
CM), the pressure in the reaction chamber was 0.75 torr. The RF frequency of the plasma CVD was 13.56 MHz, and the power density was 0.45 W / cm 2 .
【0014】これらの基板の中から3枚についてPMM
A、クロロメチル化ポリスチレン、ノボッラク樹脂をそ
れぞれ5000Åの厚みになるようにスピンコートによ
って塗布し200℃で30分間ベークして、図1(b)
に示すように、有機高分子膜3を形成した。樹脂を塗布
していない基板を1枚加えて合計4枚のサンプルに短波
長が180nmの光が発生している低圧水銀ランプ、並
びにキセノンランプを用いて光強度100mW/cm2
の条件で20時間照射した結果、樹脂を塗布していない
基板のみ窒化シリコン層が表面硬化によるストレスの増
大によって損壊して、また基板から剥がれているのが観
察されたが、他の樹脂を塗布したものには異常は見られ
なかった。以上の結果より、有機高分子膜3により遠紫
外光が遮断され窒化シリコン膜2の割れ、剥がれが生じ
ないことが分かった。For three of these substrates, PMM
A, chloromethylated polystyrene, and novolak resin were each applied by spin coating to a thickness of 5000 ° and baked at 200 ° C. for 30 minutes.
As shown in (1), an organic polymer film 3 was formed. A light intensity of 100 mW / cm 2 was obtained using a low-pressure mercury lamp in which light having a short wavelength of 180 nm was generated in a total of four samples by adding one substrate not coated with a resin, and a xenon lamp.
As a result of irradiation for 20 hours under the conditions described above, it was observed that only the substrate not coated with the resin was damaged by the increase in stress due to surface hardening and peeled off from the substrate. No abnormalities were found in those who did. From the above results, it was found that far ultraviolet light was blocked by the organic polymer film 3 and the silicon nitride film 2 did not crack or peel off.
【0015】[0015]
【発明の効果】以上の実施例に基づいて説明したよう
に、本発明によれば宇宙空間における遠紫外線に耐えら
れる表面保護膜を形成されることができ、太陽電池の信
頼性向上に効果がある。As described with reference to the above embodiments, according to the present invention, it is possible to form a surface protective film capable of withstanding far ultraviolet rays in outer space, which is effective in improving the reliability of a solar cell. is there.
【図1】本発明による実施例の工程図である。FIG. 1 is a process chart of an embodiment according to the present invention.
1 基板 2 窒化シリコン膜 3 有機高分子膜 DESCRIPTION OF SYMBOLS 1 Substrate 2 Silicon nitride film 3 Organic polymer film
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭63−3469(JP,A) 特開 昭59−50571(JP,A) 特開 昭60−124880(JP,A) 特開 昭53−139978(JP,A) 米国特許4898347(US,A) (58)調査した分野(Int.Cl.7,DB名) H01L 31/04 - 31/078 G02B 1/10 - 1/12 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-3469 (JP, A) JP-A-59-50571 (JP, A) JP-A-60-124880 (JP, A) JP-A 53-49 139978 (JP, A) U.S. Pat. No. 4,898,347 (US, A) (58) Fields investigated (Int. Cl. 7 , DB name) H01L 31/04-31/078 G02B 1/10-1/12
Claims (2)
チル化ポリスチレンからなる有機高分子膜を表面に有す
る、250℃以下の基板温度で堆積された窒化シリコン
からなる太陽電池用保護膜。1. A chloromethod formed on a light receiving surface of a solar cell.
A protective film for a solar cell made of silicon nitride deposited at a substrate temperature of 250 ° C. or less , having an organic polymer film made of chilled polystyrene on the surface.
形成された、クロロメチル化ポリスチレンからなる有機
高分子膜を表面に有する、250℃以下の基板温度で堆
積された窒化シリコンからなる太陽電池用保護膜。 2. A solar cell light-receiving surface using a GaAs material
Organic formed chloromethylated polystyrene
Deposit at a substrate temperature of 250 ° C or less with a polymer film on the surface.
Protective film for solar cells made of stacked silicon nitride.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP26031191A JP3157865B2 (en) | 1991-10-08 | 1991-10-08 | Protective film for solar cells |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP26031191A JP3157865B2 (en) | 1991-10-08 | 1991-10-08 | Protective film for solar cells |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH05102510A JPH05102510A (en) | 1993-04-23 |
JP3157865B2 true JP3157865B2 (en) | 2001-04-16 |
Family
ID=17346265
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP26031191A Expired - Fee Related JP3157865B2 (en) | 1991-10-08 | 1991-10-08 | Protective film for solar cells |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP3157865B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102185029B (en) * | 2011-04-11 | 2012-12-12 | 浙江正欣光电科技有限公司 | Method for encapsulating crystalline silicon solar cell component |
-
1991
- 1991-10-08 JP JP26031191A patent/JP3157865B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JPH05102510A (en) | 1993-04-23 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
LAPS | Cancellation because of no payment of annual fees |