Optical, Structure and Electrical Properties of Pb_1-xCd_xS Thin Films by Pulsed Laser Deposition (PLD) Method

Abstract

In this work, CdS, PbS, and Pb1-xCdxS nanoparticles with x ranged from 0.25 to 0.75 were synthesized using chemical co-precipitation mode. The pulsed laser deposition (PLD) method with laser system (Nd: YAG Laser system) was performed to make thin films of all samples which was normally performed under low gas pressure and under the following conditions; 300 mJ energy, 100 pulses, 6 Hz frequency and in the vacuum chamber on the substrates (10−2 torr). Electrical properties (D.C conductivity, Hall Effect and current-voltage measurements) of the prepared semiconductive thin films were studied using different devices. The prepared samples were characterized by UV-Vis spectroscopy (in the range 300-1100 nm) to study the optical properties, AFM and SEM to check the surface morphology (Roughness average and shape) and the particle size. XRD technique was used to determine the crystalline structure, the purity of the phase and the crystalline structure. The crystalline size averages of the nanoparticles have been found to be to 19.8, 11.0, 8.8 and 11.7 and 27.3 nm for PbS, Pb0.75Cd0.25S, Pb0.5Cd0.5S, Pb0.25Cd0.75S, and CdS respectively. The results indicate that crystalline structure of all prepared samples is cubic except CdS which shows hexagonal and cubic structure.