LAUSR

Abstract The influence of triangular grating used as a light trapping structure on the optical wave propagation within thin-film microcrystalline silicon (µc-Si:H) solar cells is investigated. A finite difference time domain (FDTD) approach is used to rigorously solve the Maxwell's equations in three dimensions. We apply two parameters of mean surface roughness ( S a ) and slope ( k ) to define triangular structure and study their influence on the absorption of µc-Si:H. When S a and k are set to 400 nm and 1, respectively, a largest enhancement of absorption is achieved. The optimum short circuit photocurrent ( J sc ) of a 1-µm thick µc-Si:H solar cell made on such a textured substrate can reach 27.0 mA/cm 2 . The carrier generation rate in the µc-Si:H material is also rigorously analyzed. Finally, we identify some key optical losses in µc-Si:H solar cells and propose for further optimizing the device design.