Spin–orbit coupling effect on electronic, linear and nonlinear optical properties of Bi2S3 and the ternary bismuth sulfide Bi2S2.75Se0.25: Ab-initio calculations

Although the relevant properties of bismuthinite Bi2S3, it was recently approved that substitution Se atoms in Bi2S3 lattice can significantly enhance its electro-optical properties. In present work, a detailed study on structural, electronic and optical Bi2S2.75Se0.25 has been carried out based first principle calculations. The simultaneous effect Se-doping spin–orbit coupling (SOC) bismuth sulfide investigated. Our calculations show exhibits narrow direct band gap 1.062 eV after inclusion (SOC). calculation carrier effective masses indicates may possess high electron mobility material which is accordance with experimental studies. linear absorption spectra for both doping (Se) increases coefficient visible range takes value up to 10105 cm?1. addition, dielectric function, conductivity energy loss function were also derived. addition content induces red shift agreement A noticeable parameters observed. stability excitons studied by estimation binding value. dispersion estimated using single oscillator model. Some nonlinearities have computed without showing large nonlinear promising candidate photonic switching applications.