Zinc -doped Cu2S thin films have been deposited onto a glass substrate using simple and economical chemical bath deposition technique (CBD). The Zn doping concentrations vary from 0 to 6 at. % in the step of 2 at. %. X-ray diffraction (XRD) measurement shows a hexagonal structure with the average crystalline size from 26.91 nm to 14.20 nm. The Fourier transform infrared (FTIR) studies have revealed the confirmation of a functional group of Cu-Zn- S lattice. The photoluminescence (PL) studies showed the occurrence of energy transition from Cu2S to dopant material of Zn sites. The blue shift observed in the transmittance spectra is due to the interstitial incorporation of Zn in the CuS matrix. The field emission scanning electron microscope (FESEM) images indicate that there is a gradual decrease in the grain size with increase in the Zn doping concentration and the flower-like structure appeared for 6 at. % of Zn. The optical energy band values are varying from 2.6 eV to 3.35 eV.