Nanotexturing and Post-Etching for Diamond Wire Sawn Multicrystalline Silicon Solar Cell

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-HNO 3 ), metal assisted chemical etching (MAC etch) solutions (AgNO 3 -HF-DI, HF-H 2 O 2 -DI) and post-etching solution (diluted KOH at 80 o C), 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 (J sc ) of 35.4 mA/cm 2 .