Elucidating the Electronic and Structural Properties of Cu2MgSnS4 through Density Functional Theory

In this study, a comprehensive density functional theory calculation is done to investigate the electronic and optical properties of Cu2MgSnS4, assessing its viability as absorber materials for photovoltaic applications. Analysis indicates that traditional approaches using the modified Becke-Johnson (mBJ) potential, similar to the General Gradient Approximation (GGA) and Local Density Approximation (LDA), do not accurately predict the experimental bandgap values, underscoring the limitations of the TB-mBJ potential for semiconductors with strongly delocalized d-electrons. To overcome this the mBJ potential is integrated with the Hubbard U correction (mBJ + U) to enhance the representation of pd hybridization and achieving a computed bandgap of 1.49 eV. Cu2MgSnS4 exhibit high optical absorption coefficients exceeding 10⁴ cm⁻¹ in the visible spectrum and lower reflectivity compared to silicon, suggesting a potential for superior solar cell performance due to enhanced light absorption capabilities.