Application of Al₂O₃ ZnO, and TiO₂ ALD thin films as antireflection coating in the silicon solar cells

Abstract

The article describes the results of a research on the surface morphology and optical properties of Al ₂O ₃, ZnO, and TiO ₂ thin films deposited by atomic layer deposition (ALD) for applications in silicon solar cells. The surface topography and elemental composition were characterised using a scanning electron microscope, and thickness was determined using an optical reflectometer. The samples were structurally examined using a Raman spectrometer. The structural variant was identified: for Al ₂O ₃ it is sapphire, for TiO ₂ it is anatase, and for ZnO it is wurtzite. Possibilities of minimising light reflection using single and double thin film systems below 5% were presented. For the first time, the effectiveness of these thin films on the current-voltage characteristics and electrical parameters of manufactured silicon solar cells was examined and compared. The solar cell with the highest efficiency of converting solar radiation into electricity was obtained for Al ₂O ₃/TiO ₂ and the efficiency of such a photovoltaic device was 18.74%.