A Facile Way of Surface Texturing of Si{100} using KOH for Silicon Solar Cells

Wet etching of Si{100} in an alkaline solution result in pyramidal structures, mostly bounded by four {111} planes. Such geometrical structures work as excellent light trapping structures and potentially help in the efficiency increment of solar cells. In this work, the effect of very low concentration potassium hydroxide (KOH) on the etched surface morphology of Si{100} is systematically studied. KOH concentration is varied from 1.0 to 0.1 wt% KOH in a step of 0.5 wt% to investigate the effect of etching concentration. Wet etching is carried at a fixed temperature of 70°C for 5 to 40 min of etching time. Samples are taken for investigation after every 5 minutes of interval. The lowest reflectance of around 12 % is measured on the samples textured in 0.5 wt% KOH for 10 min.