First-principles study on the structural, electronic, vibrational, and optical properties of the Ru-doped SnSe

SnSe has a tunable bandgap, high absorption coefficient (10⁵/cm), eco-friendly, earth-abundant material, rendering itself a solid prospect for numerous applications. Doping can influence the electronic and optical properties of the α-SnSe. Herein, we present the effect of Ru doping on the electronic, vibrational, and optical properties of the Ru_xSn_1−xSe alloy by employing the first-principles framework. The Ru_xSn_1−xSe at x = 0.0625 has an indirect bandgap of 0.87 eV. The introduction of more Ru content in the Ru_xSn_1−xSe at x = 0.125 results in the metallic characteristics of the α-SnSe. A high absorption coefficient is found for the Ru-doped α-SnSe. The phonon dispersions calculations of the Ru_xSn_1−xSe at x = 0.0625 demonstrate good dynamical stability. Also, we have used the Bethe-Salpeter equation after running the non-self-consistent G₀W₀ calculations which indicate that Ru_xSn_1−xSe at x = 0.0625 is an excellent absorber of light in the visible region and can be used for applications in solar energy conversion and optoelectronics.