Zinc concentration effect on structural, optical and electrical properties of Cd1−xZnxSe thin films

Abstract

Cd1−xZnxSe thin films with different compositions (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were deposited on glass substrates using successive ionic layer adsorption and reaction (SILAR) method at room temperature and ambient pressure. The zinc concentration (x) effect on the structural, morphological, optical and electrical properties of Cd1−xZnxSe thin films were investigated. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies showed that all the films exhibited polycrystalline nature and were covered well on glass substrates. The energy dispersive X-ray (EDAX) analysis confirmed nearly stoichiometric deposition of the films. The energy bandgap values were changed from 1.99 to 2.82eV depending on the zinc concentration. Bowing parameter was calculated as 0.08eV. The electron effective mass (me*/mo), refractive index (n), optical static and high frequency dielectric constants (ɛo, ɛ∞) values were calculated by using the energy bandgap values as a function of the zinc concentration. The resistivity values of the films changed between 105 and 107Ωcm with increasing zinc concentration at room temperature.