Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Buckling Formation on Steel-Based Solar Cell Induced by Silicone Resin Coat and Its Improvement on Performance Efficiency

실리콘 고분자 수지의 버클링을 통한 스틸기반 태양전지의 효율 향상

  • 박영준 (포스코 광양연구소 표면처리 연구그룹) ;
  • 오경석 (인하공업전문대학 화공환경과)
  • Received : 2019.02.28
  • Accepted : 2019.04.15
  • Published : 2019.08.01
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Abstract

Even though stainless steel foil is not a highly efficient material for film-type solar cell, it has strong passivation capability without additional process. In this study, silicone resin was employed during a-Si:H thin film solar cell fabrication for the purpose of planarization and electrical insulation. In the first stage of process, silicone resin was coat onto the stainless steel (STS) using spin coater with thickness of $2{\sim}3{\mu}m$ and followed by aluminum deposition using ion beam application. Unexpectedly buckling was formed during aluminum deposition process. After subsequent fabrication processes, solar cell performance was evaluated. In voltage-current data, slight increase of cell performance was obtained and interpreted by the increase of light scattering.

스테인리스 스틸을 사용한 태양전지는 효율성이 낮지만, 패시배이션을 방지하는 목적의 추가적인 막을 설치하지 않아도 되는 장점을 가지고 있다. 본 연구에서는 스테인리스 스틸을 기반으로 하는 a-Si:H 박막 태양전지 제조에 고분자 재료인 실리콘 수지를 도입하였다. 실리콘 수지의 사용 목적은 스틸표면의 평탄화와 전기 절연성을 도입하는 것이다. 초기 공정에서, 스테일리스 스틸의 표면에 실리콘 수지를 스핀코팅을 통해 $2{\sim}3{\mu}m$ 두께로 코팅하였다. 이후 증착법을 이용하여 알루미늄 박막 코팅을 시도하였다. 알루미늄 증착시, 마이크로미터 크기의 실리콘 수지 표면위에 버클링이 형성되었다. 형성된 실리콘 수지 위로 반도체층 도입 등 추가적인 박막 공정을 실시하였으며, 박막층에 유지된 버클링은 광산란 효과를 증가시켜 태양전지의 효율 향상으로 연계되었음을 알 수 있었다.

Keywords

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Fig. 1. Exemplary structure of solar cell fabricated on stainless steel substrate.

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Fig. 3. Conceptual diagram of current solar cell fabrications. It should be noted that the comparison of solar cells were the material substitution of oxides buffer layer by silicone resin in this study. (a) Planarization by sol-gel method, (b) Planarization by silicone resin application.

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Fig. 2. Surface image of SST-430. Horizontal lines as well as deep scratches were observed, which is typical in case of flatrolled product.

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Fig. 4. Surface images of silicone resin coated STS-430 observed by (a) optical microscope and (b) scanning electron microscope.

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Fig. 6. Cross-sectional images of buckled solar cell taken by SEM.

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Fig. 5. FM image of the surface of silicone resin fabricated.

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Fig. 7. Performance (current-voltage) data of silicone resin coated solar cell. Efficiency is recorded to 5.99%.

Table 1. Characteristics of Silres REN60, silicone resin [5]

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Table 2. Performance data of solar cell fabricated with silicone resin

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