Properties of Electrosynthesized Cobalt Doped Zinc Selenide Thin Films Deposited at Varying Time

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.

Investigation of optical properties of zinc oxide nanofilms deposited by electrodeposition technique

“…Similar effects on bandgap due to changes in deposition time using electrodeposition techniques have been reported by Refs. 40 and 41, demonstrating therefore a positive correlation between deposition time and thickness of the film 42 …”

“…40 and 41, demonstrating therefore a positive correlation between deposition time and thickness of the film. 42…”

Impact of Annealing and Hydrogenation on the Optical Characteristics of ZnSe/Mn and ZnSe/Co DMS Thin Films Prepared via Thermal Evaporation Method

“…The optical studies indicate the doped samples to have a red shifted absorption spectrum and a decreased bandgap about 3.3eV. It has also been investigated how doping of Mg transition metal affected the characteristics of ZnSe film and reported that the energy bandgap of film was 3.48eV, the particles was 11 nm in dimension, and the Mg was entirely bonded in the ZnSe lattice 34) , 35) . Due to the fact that most II-VI based dilute magnetic semiconductors typically exhibit anti ferromagnetic or spin glass ordering, the II-VI semiconductor doped with a magnetic element has also been researched but has only found a limited number of uses.…”