Numerical study of CdTe solar cells with p-MoTe2 TMDC as an interfacial layer using SCAPS

Abstract

The impact of molybdenum ditelluride (p-type MoTe2) transition metal dichalcogenide (TMDC) material formation as an interfacial layer between CdTe absorber layer and Mo back contact is investigated. The simulation is conducted using the solar cell capacitance simulator (SCAPS) software. Band gap energy, carrier concentration, and layer thickness of the p-MoTe2 have been varied in this study to investigate the possible influences of p-MoTe2 on the electrical properties and the photovoltaic parameters of CdTe thin film solar cells. It has been observed that a thickness of the p-MoTe2 interfacial layer less than 60 nm leads to a decrease in the cell performance. In regard to the effect of the band gap, a maximum efficiency of 16.4% at the optimum energy gap value of 0.95 eV has been obtained at a doping of [Formula: see text]. Additionally, increasing the acceptor carrier concentration [Formula: see text] of MoTe2 enhances the solar cell performance. The solar cell efficiency reaches 15.5% with [Formula: see text] of [Formula: see text] with layer thicknesses above 80 nm. This might be attributed to the possibility of forming a back surface field for the photogenerated electrons, which reduces recombination at the back contact and hence provides a low resistivity contact for holes. The results justify that the MoTe2 interfacial layer mediates an ohmic contact to CdTe films.