Surface Texturing for Crystalline Silicon Solar Cell Using RIE Equipped with Metal-Mesh
Surface texturing is an important process to enhance light absorption and to improve efficiency of a solar cell. Reactive ion etching (RIE) process is a very effective process and low-cost process, which is applicable during the dry etching processes for thin crystalline silicon solar cells with large areas. In this study, we studied a dry and free mask texturing process on crystalline silicon wafer using SF6/O2 plasmas and metal mesh in a RIE system, with special attention to the effect of the metal mesh and RIE conditions on the texture of the silicon surface. In particular, we have found an optimized RIE conditions by increasing the distance between the metal mesh and silicon wafer. We have also found that by increasing the RIE process time, with an optimized SF6/O2 ratio, pressure and RF power, it is possible to switch from a random texture, to a nm-size pyramid texture and finally to an um-size pyramid texture. This RIE system textured a crystalline wafer surface that formed about 1~2 μm pyramidal black silicon with 7~10% of reflectivity.
Liangchi Zhang, Chunliang Zhang and Zichen Chen
D. Y. Kong et al., "Surface Texturing for Crystalline Silicon Solar Cell Using RIE Equipped with Metal-Mesh", Advanced Materials Research, Vols. 328-330, pp. 747-750, 2011