Modeling of practical light management for absorption enhancement in III-V multi-junction and quantum-dot solar cells

Abstract

Light management can be used in III-V solar cells to increase quantum dot (QD) absorption without the need for excessive strain balancing. It may also be used to harden space cells against high-energy, damaging particles. A model was developed integrating simulations from electromagnetics and device physics software packages to evaluate absorption enhancement in, and performance of, III-V solar cells with textured surfaces, respectively. Simulated textures were based on what could be practically reproduced using conventional photolithography, wet etching, and substrate removal techniques. The model predicted that a nanostructured GaAs cell with a pyramid-textured back surface reflector (BSR) could enhance absorption of in the nanostructures by over 30 times that of a conventional upright design of the same thickness. The model also found that integrated light management could be used to radiation harden InGaP/GaAs/Ge space cells by thinning the GaAs subcell to less than half of the conventional thickness.