ITO, Si3N4 and ZnO:Al -- Simulation of Different Anti-reflection Coatings (ARC) for Thin Film a-Si:H Solar Cells

For thin film solar cells incorporating amorphous silicon (a-Si:H) as absorber materials, minimizing reflection from the top surface i.e. maximizing transmittance of the incoming light into the absorber for higher absorption plays an important role for the overall device performance. This paper discusses ways to minimize reflection using different anti-reflection coatings (ARC) at the top surface of the solar cell. Focus of this paper is to study the effect of ITO, Si₃N₄ and ZnO:Al as ARC on thin film aSi:H n-i-p solar cells. The influences of electrical and optical properties of the said materials are modeled using Sentaurus TCAD. Results suggest that 60 nm Si₃N₄ proves to be the best ARC among the studied three and a very thin layer of ZnO:Al e.g. 20 nm can also be effective.