Thickness dependence of optical properties of amorphous indium gallium zinc oxide thin films : effects of free-electrons and quantum confinement
Li, X. D.
Chen, T. P.
Date of Issue2015
School of Electrical and Electronic Engineering
Dielectric function of amorphous indium gallium zinc oxide (a-IGZO) thin films is found to shift significantly with the film thickness, which is attributed to the changes in both the bandgap and electron concentration of the IGZO thin films with the film thickness. The ultrathin films (film thickness < ∼20 nm) exhibit a bandgap expansion with reducing film thickness due to the quantum confinement effect; while the thicker films (thickness > ∼35 nm) demonstrate the free-electron effect, i.e. the Burstein-Moss shift and increase of free-electrons absorption with increasing electron concentration.
DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
ECS solid state letters
© 2015 The Electrochemical Society. This paper was published in ECS Solid State Letters and is made available as an electronic reprint (preprint) with permission of The Electrochemical Society. The paper can be found at the following official DOI: [http://dx.doi.org/10.1149/2.0031504ssl]. 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.