This work presents the fabrication of Zn1−xS:Snx thin films using the chemical bath deposition method and investigates the effects of Sn doping and annealing temperature on the structural, optical and electrical properties of ZnS thin films. The XRD patterns show that the relative intensities of the major diffraction peaks increase with Sn dopant incorporation and annealing temperature. Because high-temperature annealing forms several nucleation centers throughout the lattice and dopant incorporation enhances point defects leading to crystallite boundary mobility enhancement, crystallinity is also improved. UV–vis-NIR spectrophotometric studies revealed that the films have good transmittance that is larger than 75% in both visible and near-infrared regions and their optical bandgap ranges from 3.34 eV to 3.90 eV. Both the Sn content and annealing temperature cause the transmittance and the optical bandgap to rise. The absorption edge shifts towards the longer wavelength for higher Sn contents and annealing temperatures. Also, the decreased Urbach energy with increased Sn content or annealing temperature can be attributed to the reduced structural disorders and dislocations of ZnS crystals that are indicated by improved crystallinity. Electrical characterization by the two-point probe method exhibits that at higher annealing temperature grain boundary scattering limits the number of mobile carriers by increasing interatomic binding. On the other hand, due to increased carrier concentration and decreased dislocations resulting from the Sn content or annealing, localized carriers dominate in the bulk crystal state and require higher activation energy to replace an interstitial atom and excite the bulk states.

No abstract

No abstract

No abstract

The structural properties of CBD deposited CdS thin films have been studied by varying the processing parameters and Cd/S ratio of the starting Precursors in order to better understand the growth conditions. A CdS thin film was prepared on glass substrate by CBD method from a bath containing Thiourea and Ammonium hydroxide. The structural analysis was performed by X-ray Diffraction (XRD). The deposited CdS thin film was a cubic phase with small nano crystalline grains. The film was deposited at 60°C for 2 hours. After sintering the film at 300°C for 1 hour the color of the film was changed like dark yellowish and the thickness of the film was obtained 100 nm. The FTIR was done at room temperature over 350 cm-1 to 4500 cm-1 and it showed the existence of different functional group in the sample and their probable source. These studies have allowed us to establish a standard set of conditions for the fabrication of homogeneous and continuous very thin CdS films in laboratory and this preparation technique is also suitable for preparing highly efficient thin film due to its advantages such as simple, large area films, low deposition temperature and low-cost method.