Abstract

Ultrathin Cu(In,Ga)Se2 (CIGSe) solar cells open up a new door to producing large-scale cell manufacturing without high-volume materials consumption. However, this reduction in thickness of the absorber layer (CIGSe) below 1 μm is associated with two major concerns: 1- recombination enhancement at the back contact, and 2- incomplete light absorption [1]. Nanostructures at the interface of the absorber layer and the back contact can mitigate them. From the optical point of view, the nanostructures can help enhance light absorption by light trapping inside the absorber layer. The mechanisms resulting in the light trapping are scattering, near-field enhancement, and coupling into the waveguide modes [1]. Compared to metallic nanoparticles, dielectric nanostructures are more promising structures due to their absorption-free properties and their stability during high temperature processes. Dielectric nanoparticles (NPs) and dielectric nanomeshes or point contact structures (PCs), are two configurations of dielectric nanostructures [2, 3]. To the best of our knowledge, there is an unclear picture about the relationship between the ratio of dielectric coverage on the top of the back contact and the optical benefits in these two configurations. In this work, we aim at modeling three-dimensional (3-D) CIGSe solar cells incorporating SiO2 NPs and PC in COMSOL Multiphysics to opto-electronically optimize the configurations.

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