Theoretical Investigation of Light Trapping in Polycrystalline Silicon Thin-Film Solar Cells

Abstract

In this paper we present a theoretical study of light trapping in polycrystalline silicon (poly-Si) thin-film solar cells with scattering surfaces, using the commercial software Advanced Semiconductor Analysis (ASA). Light scattering in ASA is modelled by haze parameters and angular distribution functions. The effects of these functions on the calculated absorption in poly-Si thin-film solar cells are investigated. An expected result of this investigation is that the optical absorption increases with an increasing fraction of light being scattered. This increased absorption results in a higher photocurrent generation and, thus, in an improved solar cell efficiency. For poor material quality, however, a higher haze value can also result in a decrease in the short-circuit current due to increased recombination losses. Additionally, our results show that, for poor material quality, a front surface texture is to be preferred over a rear surface texture.