Honeycomb-textured structures on crystalline silicon surfaces for solar cells by spontaneous dry etching with chlorine trifluoride gas

Reflection loss of silicon solar cells can be reduced by texturization of the surfaces. In this study, single- and multi-crystalline silicon substrates were treated with chlorine trifluoride (ClF3) to create honeycomb-textured structures. We investigated surface structures and optical properties of the textured surfaces. By the treatment with ClF3 gas, the reflectance of the textured surface without anti-reflection coating was obtained to be below 20% at wavelengths between 300 and 800 nm. The solar cells using the textured substrates were fabricated and their improved performances were demonstrated.