A study on the evolution of dielectric function of ZnO thin films with decreasing film thickness
Li, X. D.
Chen, T. P.
Leong, K. C.
Date of Issue2014
School of Electrical and Electronic Engineering
Dielectric function, band gap, and exciton binding energies of ultrathin ZnO films as a function of film thickness have been obtained with spectroscopic ellipsometry. As the film thickness decreases, both real (ε1 ) and imaginary (ε2 ) parts of the dielectric function decrease significantly, and ε2shows a blue shift. The film thickness dependence of the dielectric function is shown related to the changes in the interband absorption, discrete-exciton absorption, and continuum-exciton absorption, which can be attributed to the quantum confinement effect on both the band gap and exciton binding energies.
DRNTU::Engineering::Electrical and electronic engineering
Journal of applied physics
© 2014 AIP Publishing LLC. This paper was published in Journal of Applied Physics and is made available as an electronic reprint (preprint) with permission of AIP Publishing LLC. The paper can be found at the following official DOI: http://dx.doi.org/10.1063/1.4868338. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.