Studies on selenium rich Lead Chalcogenide Pb5Se95−xZnx (X =0, 2.5, 5, and 10) thin films composed of NPs

The as-prepared Se rich (maximum of 95%) samples have been synthesized by melt-quenching method. Thin films of Pb5Se95−XZnX (X =0, 2.5, 5, and 10) have been deposited onto glass substrate (at 100 K), via thermal evaporation method. HRTEM and XRD pattern depict polycrystalline, cubic nanoparticles of average size 21 nm. The particles size has been found to be decreasing with increase in dopent content; this has been verified by FWHM values of the XRD peaks. The stoichiometries of the constituent elements of as-prepared thin films have been confirmed by the EDAX analysis. PL-emission spectra analysis reveals blue shift and peak broadening trends with increase in dopent concentration and laser irradiation time. This is the indication of decrease in particle size with increase in dopent concentration and laser-irradiation time. Thus, defects in as-synthesized lattice are increased which in turn increase the optical band gap. UV/Visible spectroscopy suggests a direct band-gap which increases with increase in Zn content and laser-irradiation time in the deposited thin films.