A study on the evolution of dielectric function of ZnO thin films with decreasing film thickness

Journal Article · Fri Mar 14 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4868338· OSTI ID:22277898

Li, X. D.; Liu, P. ^[1]; Liu, Y. ^[2]; Liu, Z. ^[3]; Leong, K. C. ^[4]

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1. School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 Singapore (Singapore)
2. State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology, Chengdu 610054 (China)
3. School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China)
4. GLOBALFOUNDRIES Singapore Pte Ltd, 738406 Singapore (Singapore)

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 (ε{sub 1}) and imaginary (ε{sub 2}) parts of the dielectric function decrease significantly, and ε{sub 2} shows 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.

• OSTI ID: 22277898
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
BINDING ENERGY
ELECTRONIC STRUCTURE
ELLIPSOMETRY
ENERGY GAP
EXCITONS
PERMITTIVITY
THICKNESS
THIN FILMS
ZINC OXIDES