The impact of SnMnO2 TCO and Cu2O as an HTL on CIGSSe solar cell performance improvement

Abstract

This paper has simulated two experimental CIGSSe thin-film solar cells (TFSCs) having a high efficiency of 20% and 22.92%. Later validates the photovoltaics results of both devices based on the experiential values of optoelectronics data. After the simulation, a compelling result was confirmed for both the experimental and simulation solar cells. Finally, different designs have also been proposed. The proposed Type-1 solar cell is designed by the addition of low resistivity, wide energy bandgap (Eg), and minimum absorption coefficient (α) based tin-doped manganese oxide (Sn1 − xMnxO2) material in a conventional solar cell instead of ZnO: B and ZnMgO: Al transparent conducting oxides (TCO) layer. Further, by matching the band energy alignment and adjusting the thickness and doping concentration of the TCO, buffer, and absorber layers, the efficiency of the proposed Type-1 TFSC has been increased from 20 to 27.75%. The proposed Type-1 solar cell has some drawbacks, such as the inability to appropriately suppress the photogenerated minority carrier recombination losses due to the absence of a hole transport layer (HTL), and the EQE is relatively lesser than the conventional solar cell. Furthermore, wide band energy and a high ‘α’ based on cuprous oxide (Cu2O) as a HTL are added between the absorber and the back ohmic contact layers in the proposed Type-1 solar cell. Then the structure becomes a proposed Type-2 TFSC. The proposed Type-2 TFSC absorbs more blue light, instantly suppressing the recombination losses and enhancing efficiency (29.01%) and EQE (97%).