Effect of n-WO3 thin film deposition on the photoelectrochemical properties of the textured p-Si electrode

The effect of WO3 thin film deposition on the photoelectrochemical properties of the textured p-Si electrodes, which were prepared by anisotropic etching of (100) p-Si in alkaline solution, have been investigated. The textured p-Si surface was covered with small pyramids having (111) planes, which led to decrease in surface reflectance and to increase in effective surface area. The photocurrents of both textured p-Si and WO3/textured p-Si electrodes tended to increase with increasing etching time up to 40 min and then slightly decreased with further etching. But the WO3/textured p-Si electrode showed relatively higher photocurrent at a less cathodic potential compared to the textured p-Si electrode without WO3 layer. These results were explained in terms of a degree of surface texturing, an intrinsic property of WO3 thin film on the surface reflectance and a charge transfer behavior due to the p-n heterojunction.