Structural characterization of Zn1-xCdxO (0?x?0.20) microrods grown by spray pyrolysis

Abstract

Zn1-xCdxO (x= 0.00, 0.05, 0.10, 0.15 and 0.20) thin films were obtained by spray pyrolysis and characterized by XRD, SEM, EDAX and optical measurements. The Zn1-xCdxO microrods are in the wurtzite crystallographic phase with (0 0 2) preferred orientation. A narrowing of the fundamental band gap from 3.30 to 3.10 eV was observed with the increasing nominal Cd content up to 20 at% due to the direct modulation of the band gap caused by Cd substitution. The undoped ZnO film showed two emission bands in the spectra: one sharp UV luminescence at ?382 nm and one broad visible emission ranging from 430 to 600 nm. The sharp peak at ?382 nm is split into two at 376 and 400 nm upon Cd doping at levels of 5 and 10 at%. However this splitting is not observed in the doped ZnO samples containing 15 at% Cd and more. It should also be mentioned that the broad peak at the range of 430-600 nm has almost disappeared in the films containing 5, 10 and 15 at% Cd. © 2009 Elsevier Ltd. All rights reserved.