A first-principles study of optoelectronic properties of Y2MS4 (M=Zn, Mg and Be): Direct bandgap ternary sulfides

The optoelectronic properties of the ternary sulfides Y2MS4 (M = Zn, Mg, and Be) are explored using computational techniques. The lattice parameters and electro-optical properties have been investigated with a full-potential linearized augmented plane wave (FP-LAPW) approach using the Generalized Gradient Approximation (GGA) through density functional theory (DFT). The TB-mBJ is utilized to compute electronic bandgap because it is reported as decent functional to generate a bandgap more accurately. The electronic band structure profile revealed the direct bandgap of 1.90, 2.61, and 1.85 eV for Y2ZnS4, Y2MgS4, and Y2BeS4, respectively. These ternary sulfides show good absorption and reflectivity in ultraviolet region of light, highlighting these sulfides' capability as a shield against ultraviolet radiation. The results of our calculations revealed the potentials of these ternary spinal sulfides Y2MS4 (M = Zn, Mg, and Be) for photovoltaic applications.