Augmented pyramidal photonic crystals for thin silicon photovoltaics

Wave-interference-based light trapping with photonic crystal structures offers a promising avenue for improving the power conversion efficiency of crystalline silicon solar cells beyond the current world record of 27.3%. Recent research on such devices has focused on structures with wet-etched inverted pyramidal pores. Using finite-difference time-domain simulations of Maxwell's equations, we demonstrate the remarkable robustness of this architecture and that in previously optimized 15 micron thick photonic crystal cells, light absorption can be further improved by 0.6% by slightly modifying the pore shape from a pyramid to that of a "golf-tee".