FABRICATION AND CHARACTERIZATION OF TWO SOURCED EVAPORATED CD-BASED II-VI THIN FILMS

Abid, Ali (2006) FABRICATION AND CHARACTERIZATION OF TWO SOURCED EVAPORATED CD-BASED II-VI THIN FILMS. Doctoral thesis, Quaid-i-Azam University of Islamabad.

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Abstract

The II-VI compound semiconductors thin films have been prepared by different methods such as electron beam vacuum evaporation, closed space sublimation and two-sourced thermal evaporation. The choice of the deposition method was based on the quality of the films required for specific application. In this research work mainly two-source evaporation technique is applied for sample preparation. The effects of deposition parameters, such as substrate and source temperature and annealing of the film, on the structural, optical and electrical properties have been studied. The structure' and composition of the films were studied by X-ray diffraction and Energy dispersive x-ray analysis respectively. Optical parameters such as refractive index, absorption coefficient, film thickness and optical band gap, were calculated from the optical transmission spectra recorded by spectrophotometer. The impact of evaporation rates of Cd and Te on CdTe thin films deposited by two sourced evaporation technique and their post doping effects arising from the diffusion of Cu and Ag to understand changes in the ,film properties were also studied. The ion exchange process is a very simple, and low cost technique. In this technique the dopant has to be in the form of ion in a solution, where the pre-prepared films are to be immersed, i.e. Ag(NO3) solution in case of silver doping and CU(NO3) solution in case of copper doping. The ion exchange parameters such as solution temperature, concentration and immersion time, and its effect on the speed of the process and further on the status of the resulting films was carefully determined and analyzed. Also the effect of post heat treatment, on the physical properties and the composition of the resulting films were studied. Ag and Cu doping of the CdTe thin films were successfully achieved.

Item Type: Thesis (Doctoral)
Uncontrolled Keywords: cd-based ii-vi thin films, ii-vi compound semiconductors thin films, glass substrates, cdte thin films
Subjects: Q Science > QC Physics
Depositing User: Muhammad Khan Khan
Date Deposited: 26 Sep 2016 08:18
Last Modified: 26 Sep 2016 08:18
URI: http://eprints.hec.gov.pk/id/eprint/1122

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