Study of structural, electronic and optical properties of oxygen and Mn substituted ZnIn2Te4 are carried out
by DFT based first principle calculation using TB-LMTO method. They are found to be direct band gap
semiconductors with band gaps 0.68 eV and 1.3 eV respectively. We have made a comparative calculation of real
and imaginary part of the dielectric functions of both ZnOIn2Te4 and ZnMnIn2Te4. We have also calculated
the static refractive index for both the compounds. Refractive index and absorption co-efficients are plotted for
both the systems for better understanding. We have found that the substitution of oxygen and Mn in ZnIn2Te4shift the major absorption peaks towards lower energy. Absorption peaks are maximum at energy 1.2 eV and
2.80 eV for ZnOIn2Te4 and ZnMnIn2Te4 respectively.