Role of Temperature on Charge Carrier Transport in Cadmium Lead Sulfide Ternary Semiconductors

Cd 1−x Pb x S ternary semiconductor compounds with x = 0–1 (in steps of 0.1) were synthesized by the co-precipitation technique. X-ray diffraction (XRD) studies revealed that the compounds were polycrystalline and that their crystal structure change from hexagonal to cubic as x varies from 0 to 1. The lattice parameters and crystallite sizes of all the samples were calculated. Surface morphology and chemical homogeneity studies were carried out by using scanning electron microscopy (SEM) and energy-dispersive x-ray analysis (EDAX). The DC electrical conductivity of these samples was measured in the temperature range 300–630 K. The studies showed three linear regions in ln σ versus 10 3 /T conductivity plots and followed Arrhenius behavior. The activation energies were evaluated in three temperature regions, and they decreased with the increase of Pb in all Cd 1−x Pb x S compounds. From conductivity studies, it is noticed that the electrical conductivity increases with increasing Pb concentration. The results are explained in terms of the ionic size of Pb and Cd, the small changes in the effective mass of electrons at a higher temperature compared to room temperature, and electron–phonon interactions.