“…This feature corresponds to donor-acceptor pair transition (DAP) between a sulfur vacancy and an indium vacancy (or) Cu (or) Zn on an indium site [15,[47][48][49] (or) band-band gap luminescence of Zn doped CuInS 2 crystals deposited on the substrate [50]. On further increase in temperature from 325 to 400 1C, there is a decrease in emission of intensities and the peak at which the maximum emission occurs slightly shifts towards shorter wavelength region.…”