Next Article in Journal
Analysis of the Influence of Starting Materials and Processing Conditions on the Properties of W/Cu Alloys
Next Article in Special Issue
Codoping and Interstitial Deactivation in the Control of Amphoteric Li Dopant in ZnO for the Realization of p-Type TCOs
Previous Article in Journal
Creep Rupture of the Simulated HAZ of T92 Steel Compared to that of a T91 Steel
Previous Article in Special Issue
Optoelectronic Properties and the Electrical Stability of Ga-Doped ZnO Thin Films Prepared via Radio Frequency Sputtering
Open AccessArticle

Carrier Compensation Induced by Thermal Annealing in Al-Doped ZnO Films

1
Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan
2
School of Engineering, Tokai University, 4-1-1, Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
*
Author to whom correspondence should be addressed.
Academic Editors: Andrea Li Bassi and Carlo S. Casari
Materials 2017, 10(2), 141; https://doi.org/10.3390/ma10020141
Received: 26 December 2016 / Revised: 23 January 2017 / Accepted: 3 February 2017 / Published: 8 February 2017
(This article belongs to the Special Issue Advances in Transparent Conducting Materials)
This study investigated carrier compensation induced by thermal annealing in sputtered ZnO:Al (Al2O3: 0.25, 0.5, 1.0, and 2.0 wt %) films. The films were post-annealed in a N2 atmosphere at low (1 × 10−23 atm) and high (1 × 10−4 atm) oxygen partial pressures (PO2). In ZnO:Al films with low Al contents (i.e., 0.25 wt %), the carrier density (n) began to decrease at annealing temperatures (Ta) of 600 °C at low PO2. At higher PO2 and/or Al contents, n values began to decrease significantly at lower Ta (ca. 400 °C). In addition, Zn became desorbed from the films during heating in a high vacuum (i.e., <1 × 107 Pa). These results suggest the following: (i) Zn interstitials and Zn vacancies are created in the ZnO lattice during post-annealing treatments, thereby leading to carrier compensation by acceptor-type Zn vacancies; (ii) The compensation behavior is significantly enhanced for ZnO:Al films with high Al contents. View Full-Text
Keywords: transparent conducting oxides; ZnO; doping; carrier compensation; mobility transparent conducting oxides; ZnO; doping; carrier compensation; mobility
Show Figures

Graphical abstract

MDPI and ACS Style

Koida, T.; Kaneko, T.; Shibata, H. Carrier Compensation Induced by Thermal Annealing in Al-Doped ZnO Films. Materials 2017, 10, 141.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop