Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10714356 | Physica B: Condensed Matter | 2011 | 6 Pages |
Abstract
ZnSe thin films have been prepared by inert gas condensation method at different gas pressures. The influence of deposition pressure, on structural, optical and electrical properties of polycrystalline ZnSe films have been investigated using X-ray diffraction (XRD), optical transmission and conductivity measurements. The X-ray diffraction study reveals the sphalerite cubic structure of the ZnSe films oriented along the (1 1 1) direction. The structural parameters such as particle size [6.65-22.24 nm], strain [4.01-46.6Ã10â3 linâ2 mâ4] and dislocation density [4.762-18.57Ã1015 lin mâ2] have been evaluated. Optical transmittance measurements indicate the existence of direct allowed optical transition with a corresponding energy gap in the range 2.60-3.00 eV. The dark conductivity (Ïd) and photoconductivity (Ïph) measurements, in the temperature range 253-358 K, indicate that the conduction in these materials is through an activated process having two activation energies. Ïd and Ïph values decrease with the decrease in the crystallite size. The values of carrier life time have been calculated and are found to decrease with the reduction in the particle size. The conduction mechanism in present samples has been explained, and the density of surface states [9.84-21.4Ã1013 cmâ2] and impurity concentration [4.66-31.80Ã1019 cmâ3] have also been calculated.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Jeewan Sharma, S.K. Tripathi,