Numerical modeling and analysis of AZO/Cu2O transparent solar cell with a TiO2 buffer layer

Abstract

In the present work, titanium dioxide (TiO2) is sandwiched as a buffer layer between n-type aluminum-doped zinc oxide (AZO) and p-type cuprous oxide (Cu2O), increasing the efficiency of metal oxide-based solar cells. The effects of the device parameters such as thicknesses, carrier concentrations, and defect densities were investigated by numerical simulation to obtain optimal performance of Cu2O-based solar cells. Our findings reveal that by the incorporation of TiO2 thin film, the efficiency of the solar cell increases remarkably from 2.54 to 5.02 %. The optimal thicknesses of the Cu2O and TiO2 layers are in the range of 10 μm and 0.1 μm, respectively. We obtained optimal photo-electric conversion efficiency of 10.17 % and open-circuit voltage of 1.35 V while achieving 8.90 mA/cm2 short-circuit current density and 84.12 % fill factor, using structure parameters of 0.2 μm AZO, 0.1 μm TiO2 and 10 μm Cu2O with optimal acceptor-type dopant density in Cu2O of 1E17 cm−3 and donor-type dopant density in TiO2 of 1E18 cm−3.