Effect of annealing temperature on structure and optical properties of CdO nanocrystaline thin film prepare by chemical bath deposition method

Abstract

CdO thin film has been deposited by chemical bath deposition method (CBD) on the glass substrate. Effect of annealing temperature( 573,623 and 673 K) on the structural and optical properties of the films has been investigated. The crystal structure investigated by X-ray diffraction method. Annealed CdO films are polycrystalline in nature with cubic structure having a preferential orientation along (1 1 1) plane. Analysis of XRD indicates that the intensities of peaks of the crystalline phase have increased with the increasing of annealing temperature. The structural parameters for the CdO thin films as the grain size, strain, dislocation density, and texture coefficient were calculated. Particle size for the preferential orientation at different annealing temperature is (16.95, 18.24 nm) for annealing temperature 623 and 673 K respectively. Optical properties study of CdO thin films using UV-vis spectrophotometer shows blue shift in the energy band gap as an indication of quantum confinement. It is observed that the band gap energy decreases with increasing of annealing temperature. The direct and indirect band gap energy values were found to be (2.95 2.87) and (1.945,1.914) eV respectively.

Temperature-dependent heterojunction ternary nanocomposite: Assessing photocatalytic and antibacterial applications

“…The calculated bandgap values for the NCPs annealed at 400 °C, 600 °C, and 800 °C were listed in Table 3 . This reduction in bandgap with increasing annealing temperature is attributed to quantum confinement effects, which result from larger crystalline sizes in the material [ 32 ]. In nanoscale materials, increased crystalline size leads to closely spaced energy levels, causing a decrease in the bandgap energy [ 33 ].…”

Effect of Order of Reagents Addition on Optical and Structural Properties of CdS Quantum Dot Prepared by Chemical Bath Deposition Technique

“…Where t is the thickness of the film, is the transmittance, which is equal to 10 -A where A is the absorbance [12,28]. In both the direct and indirect semiconductor transitions, the absorption coefficient and optical band gap (Eg) are related by Equation 3 [32]. Plots of [αhυ] 2 against photon energy (hυ) for as-deposited CdS thin films are shown in Figure 4.…”