A Comparative Study on the Optical Properties of Multilayer CdSe / CdTe Thin Film with Single Layer CdTe and CdSe Films

Abstract

CdTe and CdSe single layer thin films and CdSe / CdTe multilayer (ML) thin film were prepared by using physical vapour deposition method. Optical properties of CdSe / CdTe multilayer thin film shows different behavior due to type II band structure alignment. Energy band gap value of CdSe / CdTe ML thin film is shifted to higher value than that of single layer CdTe film. This is due to decrease in crystallite size to dimension smaller than the Bohr exciton radius of CdTe (14 nm). Crystallite size of the multilayer sample was calculated with the predictions of the effective mass approximation model (i.e., Brus model). It is observed that the photoluminescence peak of CdSe / CdTe ML thin film is red shifted compared to the peaks corresponding to individual CdSe and CdTe thin films. This may be due to the presence of type II quantum dot formation in the CdSe / CdTe heterostructure multilayer thin film. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/31939