A microscopic description of light induced defects in amorphous silicon solar cells

TL;DR

This study combines quantum and classical models to understand how microscopic atomic configurations in amorphous silicon lead to light-induced defects, affecting solar cell performance.

Contribution

It introduces a hybrid computational approach to identify atomic configurations responsible for defect formation in amorphous silicon under illumination.

Findings

Strained silicon bonds can be as important as dangling bonds in defect creation.

Defects form preferentially in regions with holes and light-induced excitations.

Results align with experimental observations on temperature, time, and pressure dependencies.

Abstract

Using a combination of quantum and classical computational approaches, we model the electronic structure in amorphous silicon in order gain understanding of the microscopic atomic configurations responsible for light induced degradation of solar cells. We demonstrate that regions of strained silicon bonds could be as important as dangling bonds for creating traps for charge carriers. Further, our results show that defects are preferentially formed when a region in the amorphous silicon contains a hole and a light-induced excitation. These results agree with the puzzling dependencies on temperature, time, and pressure observed experimentally.