Substrate Temperature Effect on the Structural and Optical Properties of Znse Thin Films

Abstract

Zinc selenide (ZnSe) thin films were deposited on to chemically and ultrasonically cleaned glass substrates at different substrate temperatures from room temperature to 200°C keeping the thickness fixed at 300 nm by using thermal evaporation method in vacuum. The structural properties of the films were ascertained by X-ray diffraction (XRD) method utilizing a diffractometer. The optical properties were measured in the photon wavelength ranging between 300 and 2500 nm by using a UV-VIS-NIR spectrophotometer. The XRD patterns reveal that the films were polycrystalline in nature exhibiting f.c.c zincblende structure with average lattice parameter, a = 5.6873Å. The grain size, strain and dislocation densities of the films have bee calculated. The optical transmittance and reflectance were utilized to compute the absorption coefficient, band gap energy and refractive index of the films. The band gap energy of the films was extracted from the absorption spectra. The direct band gap energy of the films slightly increases with substrate temperature.DOI: http://dx.doi.org/10.3329/jbas.v36i2.12969Journal of Bangladesh Academy of Sciences, Vol. 36, No. 2, 233-240, 2012

Effect of substrate temperature and oxygen partial pressure on structural and optical properties of Mg doped ZnO thin films

“…Also, the grain size of deposited films increased with substrate temperature at constant OPP (1 mTorr) which can be due to decrease in lattice imperfections and lattice coalescence. Increase of grain size can also be attributed to the relaxation of strain [28]. Above 500 1C substrate temperature, the grain size decreases, which may be due to accumulation of defects at grain boundaries.…”

Effect of Substrate Temperature on Structural and Optical Properties of CdO Thin Films

“…This increment may be due to the enhancement of crystallity order which can be clearly seen from the result of XRD and AFM. This decrease may be due to the larger grain size and lower strain in the film deposited at higher temperature [18]. …”

Synthesis and Characterization of Zinc Selenide Thin Films by Vacuum Deposition Technique

“…The glass substrate was placed above the source. The deposition rate was maintained (02 -06 Å/sec) constant throughout the sample preparations [15][16]. substrates were kept at constant temperature by a constant flow of cold water from a tap.…”