Theoretical analysis of the performance of diffraction grating back-reflectors in infrared-sensitive solar cells

摘要

The possibility of increasing the efficiency of photovoltaic (PV) cells by using a diffraction grating as a back-reflector is investigated. An enhancement coefficient is introduced as a figure of merit that accounts for the ability of the rear grating to increase the amount of energy deposited into the active layer of the cell. According to the results in this article, a diffraction-grating-like relief on the rear face of the PV cell may reduce the intensity of the specular reflection, while favouring the intensity of high-angle rays. In this way, the path-length of reflected rays increases, and so may do the efficiency of the cell.