A novel MoS2-based hybrid film as the back electrode for high-performance thin film solar cells

Abstract

MoS₂, a representative two-dimensional transition metal dichalcogenide, gains significant interest due to its unique layered structure and electronic structure. In this work, a novel MoS₂-based hybrid thin film was constructed by disordered stacking of MoS₂–NMP hybrid particles, which were mainly composed of MoS₂(NMP)₃ molecules stacking in a nearly-parallel manner through S⋯H–C hydrogen bonds. Interestingly, it presents a higher work function (5.42 eV) than Au (5.32 eV), and a unique thickness-dependent conductivity with p-type semiconductor characteristic. Using it as the back contact of CdTe solar cells, the efficiency was improved by 2.6% compared to the traditional cells, mainly from the great improvement in short-circuit current density (J_sc). This significant improvement in solar performance was ascribed to the matchable energy levels at the CdTe/MoS₂-based thin film interface and its unique thickness-dependent conductivity. This work opens a new direction for the extensive applications of TMD-based materials.