Oxygen vacancies and hydrogen in amorphous In-Ga-Zn-O and ZnO
Accepted version
Peer-reviewed
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Repository DOI
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Authors
Li, H
Guo, Y
Robertson, J
Abstract
Hydrogen is known to be present as an impurity in amorphous oxide semiconductors at the 0.1% level. The behavior of hydrogen and oxygen vacancies in amorphous In-Ga-Zn-O is studied using density functional supercell calculations. We show that the hydrogens pair up at oxygen vacancies in the amorphous network, where they form metal-H-metal bridge bonds. These bonds are shown to create filled defect gap states lying just above the valence band edge, infrared modes at about 1400 and 1520cm−1, and they are shown to give a consistent mechanism to explain the negative bias illumination stress instability found in oxide semiconductors such as In-Ga-Zn-O (IGZO).
Description
Keywords
3402 Inorganic Chemistry, 40 Engineering, 34 Chemical Sciences, 4018 Nanotechnology
Journal Title
Physical Review Materials
Conference Name
Journal ISSN
2475-9953
2475-9953
2475-9953
Volume Title
2
Publisher
American Physical Society (APS)
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Sponsorship
Engineering and Physical Sciences Research Council (EP/P005152/1)
The authors acknowledge funding from EPSRC Grants No.
EP/P005152/1.