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.
Ternary thin films of Silver Aluminium Sulphide (AgAlS 2) have been prepared by chemical bath deposition techniques. Aqueous solution of 41.5 mls containing AgNO 3 , Al 2 (SO 4) 3 , thiourea and EDTA was used, where AgNO 3 , Al 2 (SO 4) 3 , thiourea were the source of Ag + , Al + and Srespectively and EDTA was used as a complexing agent. NaOH served as pH adjuster. The films were deposited at 300K of temperature. The deposited film properties were studied using a Janway UV-VIS spectrophotometer. From the spectral analysis of absorbance and transmittance, the optical and solid properties were obtained. The properties studied include the reflectance, absorption coefficient, thickness, refractive index, extinction coefficient, optical conductivity and band gap energy. The films show high absorbance in the UV
In this work, superlattice thin films of CdSe/ZnSe were fabricated on a non-conductive glass substrate using the successive ionic layer adsorption reaction (SILAR) method to investigate their properties for possible optoelectronic applications. The SILAR process involved a total cycle time of 100 seconds for a complete SILAR cycle with a total of 12 cycles made by depositing alternative layers of CdSe and ZnSe. The deposited thin films were annealed at different temperatures and characterized to determine their optical, elemental, morphological and structural properties using UV-VIS spectroscopy, Scanning electron microscope (SEM)/energy dispersive x-ray spectroscope (EDS) and x-ray diffraction techniques (XRD). The results of the characterizations revealed that optical properties of the films such as absorbance, reflectance, refractive index and extinction coefficient are low but increased as the annealing temperature increases. The bandgap energy was found to decrease from 2.50 eV-1.90 eV for as-deposited film and those annealed between 373 K and 523 K. film thickness was found to range from 130.169 nm to 254.441 nm. The EDS results showed that the target elements such as Cd, Zn, Se and other elements traceable to the nature of substrate used were found to be present in the deposited thin film samples. The results of the XRD showed that the thin films are polycrystalline and the diffraction peaks are influenced by annealing of the sample at a higher temperature such as 523 K. The crystal parameters such as crystallite size, dislocation density and micro-strain of the film at 523 K were found to be 5.546 nm, 3.25 × 1016 l/m2 and 1.13 × 10-2. The SEM results showed that the CdSe/ZnSe superlattice films were composed of tiny nanoparticles of different dimensions and sizes with hollow which increased as the annealing temperature increased from 432 K to 523 K. Possible applications of the deposited superlattice thin films in solar cells and optoelectronic devices were established by virtue of their bandgap energy and other properties.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.