Numerical Exploration of High Voc in MoTe2-based Solar Cells with different ETL Layer Towards High Efficiency

A wide absorption range, free of dangling bonds at the surface, and adjustable band gap; such properties of Molybdenum telluride (MoTe2) give great potential as a solar absorber material for photovoltaic (PV) solar cell. In this work, a numerical analysis using SCAPS-1D software was carried out to assess the potential of a basic device structure of Pt/MoTe2/ETL (ZnSe, ZnO, and magnesium doped zinc oxide (MZO))/FTO/A1. The preliminary device has been optimized by tuning the thickness, doping density, and defect density of MoTe2-absorber and ETL (ZnSe, ZnO, and MZO) layer and the device with ZnSe as ETL layer demonstrating a photovoltaic efficiency of 30.93 %. The addition of highly doped 100 nm thick nitrogen doped copper oxide (NCO) as BSF layer suppresses the carrier recombination and enhances built-in potential of the device, as a result of improving the open circuit voltage and the device performance. However, the photovoltaic cell with MZO as ETL layer and NCO as BSF layer showing superior performance including 43.28% efficiency with a massive improvement of open circuit voltage in approximately double from 0.69 V to 1.21 V. To understand the reason behind the enhancement of VOC, the recombination and C-V analyses were conducted in the presence and absence of the BSF layer. It is revealed from such analysis that built-in potential of the device was improved and the losses due to recombination in the different regions were mitigated by incorporating NCO BSF layer. Finally, the device's performance in bifacial mode was studied and found that bifacial solar cell is effective for the proposed PVSC with further improved PV performance from 43.28 % to 50.21 % efficiency.