23-May-2013
05:49:41 IST
|
NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR) >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.50 [2012] >
IJPAP Vol.50(06) [June 2012] >
| Title: | Structural and optical properties of ZnS, PbS, Zn1-xPbxS, ZnxPb1-xS and PbZnxS1-x thin films |
| Authors: | Suhail, Mahdi Hasan |
| Keywords: | Optical properties
Structural properties
Energy gap
Semiconductor thin film
ZnS thin film
PbS thin films |
| Issue Date: | Jun-2012 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | The chemical spray
pyrolysis technique (CSPT) to prepare ZnS, PbS, PbxZn1-xS, (x=0 to 1),
PbZn1-xSx
and PbxZn1-xS,
thin films with (x = 0.01, 0.02) at
glass substrate, has been used. The result of X-ray diffraction obtained that
the films are polycrystalline and have cubic with hkl (111) and wurtize with hkl
(100) phases for ZnS films, the phase for PbS films is cubic with hkl (200) and the phases for PbxZn1-xS, Pb1-xZnxS
and PbZnxS1-x are
cubic with hkl (200). The lattice
constants (a) have been calculated as
5.939Å for PbS films, 3.36Å and 5.44Å for wurtize and cubic of ZnS films, respectively,
5.91 to 6.2Å as x varied from 0 to 1
for Zn1-xPbxS,5.92Å
for ZnxPb1-xS
films with x = 0.02, and 5.921Å for
PbZnxS1-x films
with x = 0.01. The absorption spectra
used in the wavelength range 200-1100 nm to calculate the optical energy gap
which is found to decrease with increase in the film thickness for all the
films prepared by this technique. The values of energy gap have been determined
and it was between (1.58-1.78 eV) for PbS films, (2.9-3.1eV) for ZnS films. The
energy gap of ZnxPb1-xS
films in the range (2.4-2.9) eV and (2.38-2.75) eV and of PbZnxS1-x it was (1.57-1.8) eV and (1.4-1.6) eV for x = 0.02 and x = 0.01,
respectively as the thickness increases. The optical constants, such as
refractive index (n) and extinction
coefficient (k) increase and decrease
with increase in the film thickness, respectively for all the films except ZnS
films which are having inverse properties. The dielectric constants (εr,
εi) have the same behaviour of refractive index (n) and extinction coefficient (k), respectively. |
| Page(s): | 380-386 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.50(06) [June 2012]
|
|
