다이아몬드 와이어에 의해 절단된 다결정 실리콘 태양전지의 나노텍스쳐링 및 후속 식각 연구

Abstract

The effects of nanotexturing and post-etching on the reflection and quantum efficiency properties of diamond wire sawn (DWS) multicrystalline silicon (mc-Si) solar cell have been investigated. The chemical solutions, which are acidic etching solution (HF-HNO3), metal assisted chemical etching (MAC etch) solutions (AgNO3- HF-DI, HF-H2O2-DI) and post-etching solution (diluted KOH at 80oC), were used for micro- and nano-texturing at the surface of diamond wire sawn (DWS) mc-Si wafer. Experiments were performed with various postetching time conditions in order to determine the optimized etching condition for solar cell. The reflectance of mc-Si wafer texturing with acidic etching solution showed a very high reflectance value of about 30% (w/o anti-reflection coating), which indicates the insufficient light absorption for solar cell. The formation of nano-texture on the surface of mc-Si contributed to the enhancement of light absorption. Also, post-etching time condition of 240 s was found adequate to the nano-texturing of mc-Si due to its high external quantum efficiency of about 30% at short wavelengths and high short circuit current density (Jsc) of 35.4 mA/cm2.