Comparison of the Optical and Electrical Properties of Al-Doped ZnO Films Using a Lorentz Model
1
Department of Physics, Fu Jen Catholic University, No.510 Zhongzheng Rd., Xinzhuang Dist., New Taipei City 24205, Taiwan
2
Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, No. 510 Zhongzheng Rd., Xinzhuang Dist., New Taipei City 24205, Taiwan
*
Author to whom correspondence should be addressed.
Coatings 2019, 9(1), 4; https://doi.org/10.3390/coatings9010004
Received: 29 October 2018 / Revised: 9 December 2018 / Accepted: 17 December 2018 / Published: 21 December 2018
(This article belongs to the Special Issue Design, Manufacturing and Measurement of Optical Film Coatings)
Abstract
In this research, zinc oxide (ZnO) films are doped with various amounts of Al dopants, from 0 to 13 at.%, using ion-beam co-sputtering for Zn and Al metallic targets at room temperature. The Al-doped ZnO (AZO) films appear to have lower transmittances in the UV and near-IR ranges. The electrical and optical properties of each film are successfully analyzed by using the spectroscopic ellipsometry of two Lorentz oscillators for the two lower transmittances. The optimal AZO film is deposited with an Al-dopant of 1.5 at.% at an oxygen partial pressure of 0.12 mTorr; it has the smallest resistivity of 7.8 × 10−4 Ω cm and high transmittance of > 80% in the visible regions. The free carrier concentration and mobility evaluated using ellipsometry are different from those measured using the Hall effect. This phenomenon was the result of the grain boundary scattering due to the small ~20-nm grain size of the AZO film used in this study. View Full-TextKeywords:
ZnO; Al-doped ZnO; ellipsometry; Lorentz oscillators; Hall effect; grain boundary scattering
▼
Figures
Figure 1
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
Share & Cite This Article
MDPI and ACS Style
Hsu, J.-C.; Chen, Y.-Y. Comparison of the Optical and Electrical Properties of Al-Doped ZnO Films Using a Lorentz Model. Coatings 2019, 9, 4.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
Related Articles
Article Metrics
Comments
[Return to top]
Coatings
EISSN 2079-6412
Published by MDPI AG, Basel, Switzerland
RSS
E-Mail Table of Contents Alert