Abstract
The synchrotron x-ray absorption near edge structures (XANES) technique was used in conjunction with first-principles calculations to characterize Al-doped ZnO films. Standard characterizations revealed that the amount of carrier concentration and mobility depend on the growth conditions, i.e. H2 (or O2)/Ar gas ratio and Al concentration. First-principles calculations showed that Al energetically prefers to substitute on the Zn site, forming a donor AlZn, over being an interstitial (Ali). The measured Al K-edge XANES spectra are in good agreement with the simulated spectra of AlZn, indicating that the majority of Al atoms are substituting for Zn. The reduction in carrier concentration or mobility in some samples can be attributed to the AlZn-VZn and 2Al Zn-VZn complex formations that have similar XANES features. In addition, XANES of some samples showed additional features that are the indication of some α-Al2O3 or nAl Zn-Oi formation, explaining their poorer conductivity.
Original language | American English |
---|---|
Article number | Article No. 055502 |
Number of pages | 5 |
Journal | Physical Review Letters |
Volume | 110 |
Issue number | 5 |
DOIs | |
State | Published - 28 Jan 2013 |
NREL Publication Number
- NREL/JA-5200-58142