Synergy of the ray tracing+carrier transport approach: On efficiency of perovskite solar cells with a back reflector

Abstract

[eng] We investigate the absorptance and the power conversion efficiency of a perovskite thin-film solar cell at a specular and Lambertian reflection on the cell's back-surface reflector. The analysis is done by means of the Monte-Carlo ray tracing simulations, complemented by the transfer-matrix method to account for the interference phenomenon in the local generation rate of carriers inside the semiconductor. This function is employed further in the transport equations to calculate the current-voltage characteristics of the cell. Taking the perovskite absorber CH3NH3PbI3 as an example, we analyse its efficiency, altering the absorber thickness in the interval 50 ÷ 1000 nm. We find that in the cell ( nm) the enhanced photon absorption due to the Lambertian reflection yields the efficiency increase on 2.2% as opposed to the specular reflection case. Moreover, the maximum efficiency, obtained for the perovskite layer of the thickness nm, exceeds the one obtained for the perovskite layer of the thickness nm with the specular reflection.