Performance analysis of p-MoTe₂/n-MoSe₂ -based bifacial solar cells with p⁺-N:Cu₂O as BSF layer by SCAPS-1D

Abstract

Photovoltaic solar cells (PVSC) with Molybdenum telluride (MoTe2) have received considerable attention because of their wide range of absorption, along with the absence of dangling bonds at their surface. Here, MoTe2-based PVSC with a preliminary device structure of Al/ITO/n-MoSe2/p-MoTe2/Pt was designed and estimated its performance by using the solar cell capacitance simulator in one dimension software program (SCAPS-1D). The effect of different parameters like thickness, doping density, and interface defect density of each layer was also investigated. Our investigation reveals that a moderate thickness of ~1000 nm of MoTe2 and 500 nm of MoSe2, a higher concentration of more than 1017 cm-3 for both layers and moderate defect density of below 1014 cm-3 are favorable for the better PVSC device. The effect of integrating of p+-N:Cu2O layer in the MoTe2-based PVSC as a back surface field (BSF) layer was also taken into account to improve the device performance. We also evaluated the output parameters of the optimized Al/ITO/n-MoSe2/p-MoTe2/ p+-N:Cu2O/Pt PVSC with different series and shunt resistance, back-metal work function, and working temperature. Our analysis shows that minimum series resistance, higher shunt resistance, lower working temperature, and a high back-metal work function of more than 5.35 eV are advantageous for superior PVSC due to low recombination losses, low electrical losses, and better transport of charge carriers. The best performance of 28.75% with Jsc of 34.11 mA/cm2, Voc of 0.98 V, and FF of 86.3%, was achieved by optimizing all parameters. To further improve the device performance, the bifacial mode of optimized Al/ITO/n-MoSe2/p-MoTe2/p+-N:Cu2O/Pt was considered and the PV performance of the proposed bifacial-PVSC has been also studied by using SCAPS-1D. Compared to the mono-facial device, a bifacial-PVSC device shows better performance with the bifacial factor of 77.5%, bifacial gain of 14.78%, and a higher PCE of 32.17%.