Abstract

Traditional metal rear reflector has the drawback of being a highly absorbing layer especially close to the critical angle of silicon. A Bragg reflector model based on multiple porous silicon layers is proposed to address the poor absorption of Si at longer wavelength and also to address the issue of absorption from metal back reflectors. Quarter wavelength porous silicon stack with 70% and 20% porosity is investigated as the rear reflectors for silicon solar cells, and compared with traditional metal reflectors. The potential of a Bragg reflector is investigated through simulations and experimental study with the aim to increase the absorption in Si by eliminating any optical losses caused by metal absorption.

© 2014 Optical Society of America