Optical characterisation of chemically deposited Pb_(1−x) Cd_xS films and a Pb_1−xCd_xS(n)/Si(p) heterojunction

¹ Laboratory of Advanced Electronics, LEA, Department of Electronics, University of Batna, 05000 Batna, Algeria
² Laboratory: Chimie et Chimie de l'Environnement, Department of Chemistry, University of Batna, 05000 Batna, Algeria
³ Laboratory: Céramiques de Constantine (CC), Department of physics, University of Constantine, 25000 Constantine, Algeria

Corresponding author: ounissi_abdelhamid@hotmail.com

Received: 14 September 2006
Revised: 29 September 2006
Accepted: 27 November 2006
Published online: 14 February 2007

Abstract

The optical study of transmission T(λ) and reflection R(λ) spectra has enabled us to determine compounds that possess gaps close to 1.5 eV. The conditions for preparation of a ternary compound whose gap is 1.48 eV have been used to create a Pb_1−xCd_xS-n/Si-p heterojunction. The heterojunction thus obtained presented a low yield (0.5%), as determined from the study of the J–V characteristic. In order to improve its efficiency, we have studied the effect of thermal treatment on the prepared heterojunction. X-ray diffraction has been used to determine the variation in the crystalline parameter and the ratio of cadmium in the Pb_1−xCd_xS compound, and the dependence of its gap on the cadmium concentration. We have also used the C–V technique to determine the average concentration of impurities in the Pb_1−xCd_xS compound.