No abstract

No abstract

Time optimized cobalt-doped zinc selenide thin films have been successfully electrodeposited on fluorine-doped tin oxide substrates. The films were deposited at the varying time of 1 min, 3 mins, and 5 mins respectively. Film thickness, optical, structural, electrical, and morphological properties of the deposited thin films were evaluated. Film thickness estimated using the gravimetric method increased from 294.35 nm to 399.62 nm as deposition time increased. Optical properties showed that the absorbance of the films ranged from 13.58% to 83.15% and was found to increase as deposition time increased. Transmittance ranged from 24.40% to 73.15% and was found to decrease as deposition time increased. The reflectance of the films was found to be low while the energy band gap ranged between 2.10 eV and 2.85 eV. Structural properties confirmed the deposition of ZnSe thin film with crystallite size values that fall between 14.68 nm and 18.60 nm. Dislocation density is ranged from 4.66 × 1015 lines/m2 to 2.97 × 1015 lines/m2 while microstrain ranged between 8.53 × 10-3 and 5.83 × 10-3. Crystallite sizes of the films were found to increase as deposition time increased while dislocation density and microstrain were found to decrease as deposition time increased. Electrical properties showed that the deposited films are semiconducting films with electrical resistivity values of 1.54 × 105 Ω cm-1.83 × 104 Ω cm and electrical conductivity values of 6.30 × 10-6 S/cm-5.47 × 10-5 S/cm. The micrograph of the films showed that the films were made up of nanoparticles and nanofibres of different dimensions. Energy-Dispersive X-Ray Spectroscopy (EDS) spectra of the films confirmed the presence of cobalt, zinc, and selenium.

Cobalt Selenide thin films were fabricated using Successive Ionic Layer Adsorption and Reaction (SILAR) deposition technique at different SILAR cycles. The precursors for Cobalt and Selenium ions were CoCl2.6H2O and Na2SeSO3 respectively. Optical properties and thickness of the deposited films were studied to determine the effect of number of SILAR cycles on these properties. The optical absorbance of the films was found to decrease as wavelength increases and increases as SILAR cycle increases. Transmittance of the CoSe thin films was found to increase as the wavelength increases but decreases as number of SILAR cycles increased. The extinction coefficient of CoSe thin films decreases as wavelength increases but increases as the SILAR cycles increases. The energy band gap of CoSe thin films deposited decreases from 2.47 eV to 2.20 eV as number of SILAR cycles increases and film thickness increases from 92.96 nm and 225.63 nm. Structural properties of deposited cobalt selenide thin films showed that they correspond to orthorhombic phase of CoSe2 crystal structure of cobalt selenide thin films with crystallite size ranging from 7.63 nm to 13.07 nm.