Implications of light-induced defects on the performance of amorphous silicon alloy p-i-n solar cells

Abstract

We present results of computer simulations of the performance of amorphous silicon alloy p‐i‐n solar cells upon prolonged light exposure, for a range of device thicknesses for illumination through both the n⁺ and p⁺ layer. Our model realistically describes the dominant loss mechanisms in these devices, which are shown to be bulk recombination. We show how an understanding of the light‐induced degradation can lead to designing cells with improved stability by suitable modifications to the optical absorption characteristics of the intrinsic layer near to where light enters the device. Finally, by relating defect creation to the minority‐carrier diffusion length, we have calculated solar cell performance versus time in the absence of annealing for a range of device thicknesses for global AM1.5 illumination through both the n⁺ and p⁺ layers.