Effects of multi- Deposition on the structural and optical properties of CdS nanocrystalline thin film prepared by CBD technique.

Jamal F Mohammad

doi:10.30723/ijp.v11i20.383

Abstract

Cadmium sulfide (CdS) nanocrystalline thin films have been prepared by chemical bath deposition (CBD) technique on commercial glass substrates at 70ºC temperature. Cadmium chloride (CdCl2) as a source of cadmium (Cd), thiourea (CS(NH2)2) as a source of sulfur and ammonia solution (NH4OH) were added to maintain the pH value of the solution at 10. The characterization of thin films was carried out through the structural and optical properties by X-ray diffraction (XRD) and UV-VIS spectroscopy. A UV-VIS optical spectroscopy study was carried out to determine the band gap of the nanocrystalline CdS thin film and it showed a blue shift with respect to the bulk value (from 3.9 - 2.4eV). In present work effects of thickness on the structural and optical properties of CdS nanocrystalline thin films were discussed.

Highlights

The II-VI binary semiconducting compounds, belonging to the cadmium chalcogenide family (CdS, CdSe, CdTe) are considered very important due to their potential use in photoconductive devices and solar cells [1,2,3]
The deposition of Cadmium sulfide (CdS) film has been explored by various techniques, such as thermal evaporation, sputtering, molecular beam epitaxy, spray pyrolysis, chemical bath deposition (CBD) [8]
CdS thin films, which were deposited on glass, can have either a hexagonal or a cubic structure or, a mixture of them, depending on the preparation conditions [12]

Summary

Introduction

The II-VI binary semiconducting compounds, belonging to the cadmium chalcogenide family (CdS, CdSe, CdTe) are considered very important due to their potential use in photoconductive devices and solar cells [1,2,3]. One of the most important properties of this semiconductor material to be considered for this application is its energy band gap (Eg). CdS thin films of good quality, adherence and reproducible properties have been grown by the CBD technique. A large number of studies are carried in order to produce CdS thin films with good optoelectronic properties suitable for photovoltaic applications. For this purpose several properties are required for the CdS thin films: (i) relatively high transparency and not too thick to avoid absorption in the buffer layer and favors the absorption in the CIS layer (ii), not too thin to avoid the short circuiting (iii) relatively large conductivity to reduce the electrical solar cells losses and

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Results

Conclusion