Maskless texturization of phosphorus-diffused layers for crystalline Si solar cells by plasmaless dry etching with chlorine trifluoride gas

摘要

Reflection loss of silicon solar cells can be reduced by texturing the surfaces. We investigated the texturization process for crystalline Si solar cells using chlorine trifluoride (ClF_3) gas treatments. Reflectance of textured surfaces was reduced to below 10 at the wavelength of 600 nm. However, the efficiency increase for the random-textured solar cells was below 10 and was much less than the increase for the absorbed light in the substrates after texturization. In this study, we tried to improve the electrical characteristics of textured cells by modifying the fabrication process. The diffused layers were treated with chlorine trifluoride gas to form textured structures. The reflectance of the textured surface, obtained by the maskless etching with ClF_3, was approximately 17.8 at the wavelength of 600 nm. Solar cells with textured substrates were fabricated and their improved performance was demonstrated.