Results
Title

Structural modification and band gap engineering of sol-gel dip-coated thin films of ZnMgO alloy under vacuum annealing.

Authors

NARAYANAN, NRIPASREE; DEEPAK, N

Abstract

In the present study, we investigated the effect of vacuum annealing on the structural and optical properties of sol-gel dip-coated thin films of ZnMgO alloy. XRD studies revealed that all these films were polycrystalline with hexagonal wurtzite structure and there was no trace of additional phases other than ZnO. With increase in annealing temperature, the samples showed preferred orientation along the c-axis, (0 0 2) plane and also peak narrowing and peak shift towards higher angles. The calculated values of mean crystallite size increased with annealing temperature indicating the improvement in crystallinity. Heat treatment caused lattice contraction and a decrease in film thickness. The optical transmittance in the visible spectral range enhanced with increase in annealing temperature while the fundamental absorption edge in the near ultra-violet region got red-shifted with annealing. The calculated values of optical energy gap of the samples showed a decrease with heat treatment due to the improvement in crystallinity during annealing and hence the subsequent decrease in quantum size effect.

Subjects

SOL-gel processes; SOL-gel materials; THIN films; POLYCRYSTALS; CRYSTALLINITY

Publication

Pramana: Journal of Physics, 2016, Vol 87, Issue 6, p1

ISSN

0304-4289

Publication type

Academic Journal

DOI

10.1007/s12043-016-1300-0