A simulation approach for device structure and thickness optimization of silicon heterojunction solar cells featuring TiO2 as carrier-selective contact

Abstract Transition metal oxide (TMO) based thin film contacts have gained attention in heterojunction solar cells because of their low fabrication cost and high-efficiency potential. In this work, a simulation study of heterojunction Si solar cells with TiO2 as a carrier selective layer was carried out with the aid of AFORS-HET software. We have investigated the effects of variations in thicknesses of the front-side carrier selective layer (TiO2), c-Si absorber, and back-side a-Si layer on the photovoltaic performance of TiO2/c-Si(p)/a-Si(p) heterojunction solar cells. The simulation results show that the device structure with 1 nm TiO2, 300 µm Si and 1 nm a-Si has the highest efficiency of 24.27%. The structure with 100 µm c-Si thickness also shows a high efficiency of 23.2%. It indicates that carrier-selective contacts can provide excellent performance even with thin Si and are highly suitable for reducing the material cost of Si photovoltaics.