Numerical evaluation of bi-facial ZnO/MoTe2 photovoltaic solar cells with N-doped Cu2O as the BSF layer for enhancing VOCvia device simulation

Abstract

Molybdenum telluride (MoTe₂) shows great promise as a solar absorber material for photovoltaic (PV) cells owing to its wide absorption range, adjustable bandgap, and lack of dangling bonds at the surface. In this research, a basic device structure comprising Pt/MoTe₂/ZnO/ITO/Al was developed, and its potential was assessed using the SCAPS-1D software. The preliminary device exhibited a photovoltaic efficiency of 23.87%. The integration of a 100 nm thick nitrogen-doped copper oxide (N-doped Cu₂O) layer as a hole transport/BSF layer improved the device performance of the MoTe₂/ZnO photovoltaic solar cell (PVSC), increasing the open circuit voltage (V_OC) from 0.68 V to 1.00 V and, consequently, its efficiency from 23.87% to 34.45%. Recombination and C–V analyses were conducted across various regions of the device with and without the BSF layer. The results of these analyses revealed that this improvement in the device performance mainly stemmed from a decrease in recombination losses at the absorber/BSF interface and an increase in the built-in potential of the device, resulting in improved V_OC and photovoltaic efficiency. Additionally, the performance of the device in a bifacial mode was studied. The calculated bifacial factor (BF) values suggested that there were negligible additional losses affecting some parameters when the solar cell was under backside illumination and emphasized the potential for improved energy harvest in bifacial solar cells without significant drawbacks.