Issue 43, 2020

Hydrogen doping in wide-bandgap amorphous In–Ga–O semiconductors

Abstract

Microscopic mechanisms of the formation of H defects and their role in passivation of under-coordinated atoms, short- and long-range structural transformations, and the resulting electronic properties of amorphous In–Ga–O with In : Ga = 6 : 4 are investigated using computationally-intensive ab initio molecular dynamics simulations and accurate density-functional calculations. The results reveal a stark difference between H-passivation in covalent Si-based and ionic oxide semiconductors. Specifically, it is found that hydrogen doping triggers an extended bond reconfiguration and rearrangement in the network of shared polyhedra in the disordered oxide lattice, resulting in energy gains that outweigh passivation of dangling O-p-orbitals. The H-induced structural changes in the coordination and morphology favor a more uniform charge density distribution in the conduction band, in accord with the improved carrier mobility measured in H-doped In–Ga–O [W. Huang et al., Proc. Natl. Acad. Sci. U. S. A., 2020, 117, 18231]. A detailed structural analysis helps interpret the observed wide range of infrared frequencies associated with H defects and also demonstrate that the room-temperature stability of OH defects is affected by thermal fluctuations in the surrounding lattice, promoting bond migration and bond switching behavior within a short picosecond time frame.

Graphical abstract: Hydrogen doping in wide-bandgap amorphous In–Ga–O semiconductors

Article information

Article type
Paper
Submitted
16 ⵢⵓⵍ 2020
Accepted
11 ⵛⵓⵜ 2020
First published
14 ⵛⵓⵜ 2020

J. Mater. Chem. C, 2020,8, 15436-15449

Author version available

Hydrogen doping in wide-bandgap amorphous In–Ga–O semiconductors

J. E. Medvedeva and B. Bhattarai, J. Mater. Chem. C, 2020, 8, 15436 DOI: 10.1039/D0TC03370G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements