Effects of film thickness and stoichiometric on the electrical, optical and photodetector properties of CdS quantum dots thin films deposited by chemically bath deposition method at different bath temperature

Abstract

CdS quantum size thin films were prepared by chemical bath deposition at various bath temperatures. The effect of film thickness and stoichiometry on the electrical, optical and photodetector properties was investigated. The thickness of films at bath temperature from 50 to 80 °C was 200–500 nm for multiple dip process. The optical band gap of nanofilms decreased by the increase of bath temperature, however the sub band gap of nanofilms increased by the increase of bath temperature. The photoluminescence spectra showed three emission peaks located at wavelength of 420, 460 and 490 nm which is due to violet, blue and green bands level respectively. The photodetector properties are related to deposition parameters which are discussed.