Study of the mechanical properties of OsS2 and its enhanced optoelectronic performance under Fe/Ru doping

[Display omitted] •First principle investigations of OsS2 in pyrite type structure.•The semiconducting nature with a narrow band gap is expected.•The doping of Os site with Fe and Ru improves the band gap.•Enhancement of optical properties like absorption coefficient, reflectivity, refractive index, and optical conductivity when doped.. In the present manuscript, we report a systematic investigation of the structural, electronic, and optical properties including the elastic behaviour of erlichmanite (OsS2), using FP-LAPW method. The effect of exchange correlation functional when treated with GGA, this ductile semiconductor shows an electronic band gap of 0.34 eV that has been enhanced to 0.75 eV when mBJ potential is employed. The band gap of OsS2 further widens when Os site is doped with Fe/Ru with its highest value of 1.83 eV when 75 % of Os is replaced with Fe. The addition of dopant also improves the refractive index of the sample with highest amplitude when 75 % Fe doping and the optical absorption coefficient reaches its highest limit of 8.7 × 105 cm−1 and 9.1 × 106 cm−1 in the visible energy range for 75 % Fe and Ru doping, respectively.