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.