Effect of vacuum annealing and substrate temperature on structural and optical properties of ZnIn2Se4 thin films
G.F.Salem; M.M. El-Nahass; A.A. Attia,; H.A.M. Ali,; M.I. Ismail.;
Abstract
Zinc indium selenide (ZnIn 2 Se 4 ) thin films were prepared by the thermal evaporation technique with high deposition rate. The effect of thermal annealing in vacuum on the crystallinity of the as-deposited films was studied at different temperatures (523, 573 and 623 K). The effect of substrate temperature (623 K) for different thickness values (173, 250, 335 and 346 nm) on the optical parameters of ZnIn 2 Se 4 was also studied. The structural studies showed nanocrystalline nature of the room temperature (3001 < ) deposited films with crystallite size of about a few nanometers. The crystallite size increased up to 31 nm with increasing the annealing temperature in vacuum. From the reflection and transmission data, the refractive index n and the extinction coefficient k were estimated for Znln 2 Se 4 thin films and they were found to be independent of film thickness. Analysis of the absorption coefficient data of the as-deposited films revealed the existence of allowed direct and indirect transitions with optical energy gaps of 221 eV and 171 eV, respectively. These values decreased with increasing annealing temperature. At substrate temperature of 623 K, the direct band gap increased to 241 eV whereas the value of indirect band gap remained nearly unchanged. The dispersion analysis showed that the values of the oscillator energy E0, dispersion energy Ed, dielectric constant at infinite frequency E, and lattice dielectric constant EL were changed appreciably under the effect of annealing and substrate temperature. The covalent nature of structure was studied as a function of the annealing and substrate temperature using an empirical relation for the dispersion energy Ed. Generalized Miller's rule and linear refractive index were used to estimate the nonlinear susceptibility and nonlinear refractive index of the thin films. © 2013 Elsevier BY. All rights reserved.
Other data
Title | Effect of vacuum annealing and substrate temperature on structural and optical properties of ZnIn2Se4 thin films | Authors | G.F.Salem ; M.M. El-Nahass ; A.A. Attia, ; H.A.M. Ali, ; M.I. Ismail. | Keywords | ZnIn2Se4 films -X-ray diffraction- Annealing Substrate temperature- Optical properties | Issue Date | 1-Jan-2013 | Journal | Physica B: Condensed Matter | DOI | 10.1016/j.physb.2013.05.012 | Scopus ID | 2-s2.0-84886945740 |
Attached Files
File | Description | Size | Format | |
---|---|---|---|---|
Effect ofvacuumannealingandsubstratetemperatureonstructural.pdf | 1.11 MB | Adobe PDF | View/Open |
Similar Items from Core Recommender Database
Google ScholarTM
Check
Citations
15
in scopus
views
25
in Shams Scholar
downloads
16
in Shams Scholar
Items in Ain Shams Scholar are protected by copyright, with all rights reserved, unless otherwise indicated.