Search

Zinc sulphide (ZnS) is a semiconductor used extensively in optoelectronic devices. It is frequently used as a buffer layer in highly efficient solar cells due to its ecologically favourable qualities. In this work, we have studied the effect of ammonia during the synthesis of ZnS thin film using the chemical bath deposition (CBD) method for optical properties. The CBD route uses metal ions so that there are no hydroxide products, and the deposition process occurs in the ion-by-ion process. The formation of the ZnS thin films has been examined by x-ray diffraction. The resulting films contain a polycrystalline structure, a cubic and hexagonal mixture, and a strong preference for orientation along the (111) plane of the main cubic phase. The SEM and TEM images have shown the effect of ammonia on grain size, and both types of films have a thick, homogenous surface morphology. The optical properties of ZnS thin films with NH 3 were better than without, determined by UV/Vis spectroscopy. Among all synthesized materials, ZnS thin film with NH 3 and without stirring exhibits the highest optical quality and film crystallization. The obtained results indicated that it is optimistic in optoelectronics and photovoltaic applications. • Synthesised the nanocrystalline ZnS thin film without and addition of ammonia using a simple chemical bath deposition method. • XRD, SEM, TEM studies confirmed the growth of nanocrystalline ZnS thin film and effect of ammonia. • The grain size of the ZnS thin film decreases by adding NH 3 complex agent. • The optical properties are also improved via the addition of a complex agent. [ABSTRACT FROM AUTHOR]

In this manuscript, we have grown the AgMoO 3 thin film by a simple thermal evaporated method. To attain the best quality film, post-annealing the grown thin films for different temperatures (450 K, 500 K, and 550 K) was performed. The XRD data shows the formation of AgMoO 3 thin film and different secondary phases. The SEM data have shown the small spherical grains on the thin film surface, which confirm the creation of extra secondary phases and the cracks on the film with post-annealing due to intrinsic stress. The absorption coefficient and energy bandgap have also increased with the post-annealing temperature. The Seebeck data indicated an enhancement in Seebeck coefficient value from 237 to 410 μV/K as the as-grown to post-annealed samples. The electrical conductivity measurements also showed an increasing trend. The Seebeck coefficient and electrical conductivity enhancement were increased by creating a different secondary phase that caused the carrier localization. Improved mobility of carriers due to the change in crystal structure has resulted in an increased power factor of 1.19 × 10−3 Wm−1K−2. • Synthesized the AgMoO 3 thin film using a simple thermal evaporated method and post annealed at 450 K, 500 K, and 550 K. • The fabrication of AgMoO 3 thin film was confirmed by XRD and SEM. • The absorption coefficient and energy band-gap have also increased with the post-annealing temperature. • The power factor value of AgMoO 3 thin film was increased with rising the post-annealing temperature. [ABSTRACT FROM AUTHOR]

Abstract: Structural, electronic and optical properties of Ca x Cd1− x O (0⩽ x ⩽1) in rocksalt phase are calculated using full potential linearized augmented plane wave (FP-LAPW) method. The results show that the bandgap as well as structural and optical properties of the compound varies with the Ca concentration. The substitution of Cd by Ca, larger than 25%, transforms the ternary oxide from semi-metallic into indirect bandgap semiconductor. The bandgap increases with the increase in calcium while the bulk moduli decreases. The density of states shows that maximum contribution to the valence and conduction bands are due to the Cd-4d, O-2p, Ca-3p and Ca-3d states. Optical properties in the incident photon energy range 0–30eV reveal that the real part of the complex dielectric constant decreases with the increase in the Ca concentration. [Copyright &y& Elsevier]