Evaluation of a New Acid Solution for Texturization of Multicrystalline Silicon Solar Cells

Abstract

Surface texturing methods using an alkaline solution for monocrystalline Si (c-Si) solar cells have been widely accepted to improve cell performance. However, multicrystalline Si (mc-Si) cells are difficult to be texturized by alkaline etching, because the grains in the substrates are randomly oriented. In this study, we considered a HF/HNO3/H2SO4acid solution for texturing the mc-Si cells. We evaluated the morphology of the textured surfaces and the reflectance spectra from the surfaces. The deep dimple textured structures are formed on the surfaces for only 30 seconds of the acid texturing process. This behavior results from the effect of H2SO4in the solution. This process obtains up to 14.7% conversion efficiencies of the acid textured cells. These conversion efficiencies are up to 1.3 times larger than those of the mirror-etched cells.

Random-Texturing of Phosphorus-Doped Layers for Multi-Crystalline Si Solar Cells by Plasmaless Dry Etching

“…However, an alkaline solution is not effective for texturing multi-crystalline Si. Random-textured structures created by wet etching with mixed acid solutions, HF/HNO 3 /CH 3 COOH (Nishimoto et al, 1999;Hauser et al, 2004;Nievendick et al, 2012) or HF/HNO 3 /H 2 SO 4 (Watanabe et al, 2013) for multi-crystalline Si have been investigated, but they are insufficient for obtaining a low reflectance. Moreover, the wet process will be difficult for thin substrates with low mechanical strength in the future.…”

Block Textured a-Si:H Solar Cell

“…Surface texturing can reduce the light reflectance on the surface of cells quite efficiently and achieve enhanced light absorption inside the cells compared to flat surface cells [13,14]. A low cost surface texturing method by wet etching using an alkaline solution is used widely for improving the short circuit current of the cells [15,16]. To achieve the high efficiency, the transmitted light should be trapped in the solar cells to avoid escaping from the solar cell surfaces until it is absorbed [17].…”