Formation of p-type CdS thin films by laser-stimulated copper diffusion

Abstract

A new fabrication technique of p-type CdS thin films by He-Ne laser illumination of bilayer Cu-nCdS structures at room temperature was investigated. The n-type CdS films were obtained by vacuum evaporation in a quasi-closed volume. X-ray diffraction was used to provide crystalline structure and composition data of CdS films and Cu-CdS structures. The band gap of CdS films was estimated from the optical transmission spectra. The hot probe and Hall effect studies were used for the determination of conductivity type and concentration of charge carriers in films. The formation of a p-n homojunction in CdS films or conversion of the film all over to the p-type, depending on the duration of laser illumination, was shown by I-V characteristics, the photovoltaic, the hot probe and Hall effect measurements. Analysis of concentration distributions of Cu in CdS films, arising as a result of laser-accelerated diffusion, by energy dispersive x-ray spectroscopy gave the effective diffusion coefficient of copper, D = 8 × 10-12 cm2 s-1 at T = 25 °C.

Degradation of Cd-yellow paints: Ab initio study of native defects in {10.0} surface CdS

“…In general, cadmium sulfide is a direct band gap semiconducting compound and its physical properties have been widely studied not only in the field of cultural heritage, but also in fundamental science as well as in optoelectronic applications like solar cells [22], lasers [23], and recently in nanotechnology [24]. These studies focus on point defects in CdS both in bulk wurtzite and zincblende phase.…”

Preparation and properties of CdS thin films deposited by chemical bath deposition

“…Among various techniques which are used to prepare thin CdS, such as physical vapour deposition (PVD), close-spaced-sublimation (CSS) [4,5], screen printing (SP) [6] and MOCVD [7], chemical bath deposition (CBD) is the most widely used for its low cost and simpleness. Otherwise, it is easy to control the growth rate and can produce reproducible, uniform and adherent films [8][9][10]. In this work, the changes of morphology, structure and optical properties with different pH values and annealing treatments will be investigated.…”

On the mechanism of current-transport in Cu/CdS/SnO2/In–Ga structures

“…Cadmium sulfide (CdS) film of the II-VI group is generally used as a wide band gap 2.42 eV semiconductor. CdS is one of the best materials for the fabrication of high efficiency polycrystalline thin film solar cells, either based on cadmium telluride or copper indium diselenide (CIS) [3][4][5]. On the other hand, the Cu-CdS bilayer systems are used for the preparation of metal-coated semiconductor nanocrystals which are of great interest for the fabrication of optical and electroluminescent devices [5,6].…”