FIZIKA A 13 (2004) 4 , 137-150

STRUCTURAL CHARACTERIZATION AND OPTICAL PROPERTIES OF ANNEALED CdIn₂Se₄ THIN FILMS

A. M. SALEM^a,1 and S. H. MOUSTAFA^b

^aElectron Microscopy and Thin Films Department, National Research Centre, Cairo, Egypt
^bHelwan University, Faculty of Science, Cairo, Egypt
¹E-mail address: [email protected]

Received 24 April 2004;    Accepted 20 December 2004
Online 2 February 2005

CdIn₂Se₄ chalcogenides thin films were prepared by thermal evaporation process. The effect of thermal annealing in vacuum on the growth characteristics of the deposited films was studied using X-ray and transmission electron microscopy techniques. It was observed that the as deposited films (300 K) were poorly crystalline. The degree of crystallinity increases with increasing the annealing temperature from 300 to 500 K. The compositional elemental analysis of CdIn₂Se₄ thin films annealed at 500 K was found to be nearly stoichiometric, however, films annealed in vacuum at 575 K partially dissociated into two binary phases with CdIn₂Se₄ as the major phase. The effect of the annealing temperature on the dispersion of the refractive index of the deposited films was investigated and analyzed within the single effective-oscillator approach. Changes of the dispersion parameters were also investigated as a function of the annealing temperature. Analysis of the optical absorption data revealed the existence of allowed direct and indirect optical transitions, and both values of energy gaps decrease with increasing annealing temperature.

PACS numbers: 68.55.-a, 68.60.Dv, 68.90.+g
UDC 538.975

Keywords: CdIn₂Se₄, thin film, X-ray analysis, TEM, annealing, refractive index, optical absorption

Copyright by The Croatian Physical Society
For problems or questions please contact [email protected]