Nano-Texturing of Silicon Wafers Via One-Step Copper-Assisted Chemical Etching

Nano-texturing of a silicon surface has been achieved via one-step copper-assisted chemical etching (CACE), which offers a simple approach for large-scale production of inverted pyramid textured silicon surfaces. The effects of H 2 O 2 concentration, etching time and reaction temperature on the inverted pyramid-like structure and anti-reflective ability were systematically investigated. The results show that the lowest average reflectivity (4.3%) in the wavelength range of 300~1000 nm was obtained under the optimum conditions of 0.06 mol/L copper nitrate, 3 mol/L H 2 O 2 concentration and 2 mol/L hydrofluoric acid (HF) at 60 °C for 5 min. The formation mechanism of the inverted pyramid structure is discussed and can be attributed to the moderate catalytic activity of nanocopper particles that induce etching preferentially along the non- directions of the silicon. The inverted pyramid structures, with the excellent anti-reflectivity, have potential application in the fabrication of solar cells compatible with the semiconducting industry.