Light confinement in e‐beam evaporated thin film polycrystalline silicon solar cells

Abstract

Abstract Polycrystalline Si thin‐film (poly‐Si) solar cells need effective light‐trapping to compensate for the moderate absorption. Recent developments in the poly‐Si cell technology focus on film fabrication by e‐beam evaporation due to its manufacturing benefits, such as a very high deposition rate above 15 nm/s and inline compatible process. However, evaporated poly‐Si cells exhibit limited compatibility with textured glass. In this Letter, the coupling of the light in the absorber layer is enhanced by introducing a rough interface at the back of the solar cells. This increases the conversion efficiency from 6% to 7.1% for, respectively, planar and back textured interface with current density of 26.6 mA/cm 2 for only 3.6 μm absorber thickness. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)