Optical enhancement and losses of pyramid textured thin-film silicon solar cells

Abstract

The optical enhancement and losses of microcrystalline thin-film silicon solar cells with periodic pyramid textures were investigated. Using a finite difference time domain algorithm, the optical wave propagation in the solar cell structure was calculated by rigorously solving the Maxwell’s equations. The influence of the profile dimensions (the period and height of the pyramid) and solar cell thickness on the quantum efficiency and short circuit current were analyzed. Furthermore, the influence of the solar cell thickness on the upper limit of the short circuit current was investigated. The numerically simulated short circuit currents were compared to fundamental light trapping limits based on geometric optics. Finally, optical losses in the solar cell were analyzed. After identifying these key losses, strategies for minimizing the losses can be discussed.