Amorphous gallium oxide sulfide: A highly mismatched alloy

Maribel Jaquez; Petra Specht; Kin Man Yu; Wladek Walukiewicz; Oscar D. Dubon

doi:10.1063/1.5111985

Amorphous gallium oxide sulfide : A highly mismatched alloy

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

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Author(s)

Maribel Jaquez
Petra Specht
Kin Man Yu
Wladek Walukiewicz
Oscar D. Dubon

Related Research Unit(s)

Department of Physics

Detail(s)

Original language	English
Article number	105708
Journal / Publication	Journal of Applied Physics
Volume	126
Issue number	10
Online published	13 Sept 2019
Publication status	Published - 14 Sept 2019

Link(s)

DOI	DOI https://doi.org/10.1063/1.5111985 Final Published version
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Attachment(s)	Documents 37504427.pdf Final Published version, 1.89 MB, PDF Publisher's Copyright Statement COPYRIGHT TERMS OF DEPOSITED FINAL PUBLISHED VERSION FILE: This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Maribel Jaquez, Petra Specht, Kin Man Yu, Wladek Walukiewicz, and Oscar D. Dubon, "Amorphous gallium oxide sulfide: A highly mismatched alloy", Journal of Applied Physics 126, 105708 (2019) and may be found at https://doi.org/10.1063/1.5111985.
Link to Scopus	https://www.scopus.com/record/display.uri?eid=2-s2.0-85072345100&origin=recordpage
Permanent Link	https://scholars.cityu.edu.hk/en/publications/publication(ebd34595-1df1-4206-9ab4-4f7f8020b3bb).html

Abstract

Stoichiometric gallium oxide sulfide Ga₂(O_{1 - x}S_x)₃ thin-film alloys were synthesized by pulsed-laser deposition with x ≤ 0.35. All deposited Ga₂(O_{1 - x}S_x)₃ films were found to be amorphous. Despite the amorphous structure, the films have a well-defined, room-temperature optical bandgap tunable from 5.0 eV down to 3.0 eV. The optical absorption data are interpreted using a modified valence-band anticrossing model that is applicable for highly mismatched alloys. The model provides a quantitative method to more accurately determine the bandgap as well as an insight into how the band edges are changing with composition. The observed large reduction in energy bandgap with a small sulfur ratio arises from the anticrossing interaction between the valence band of Ga₂O₃ and the localized sulfur level at 1.0 eV above the Ga₂O₃ valence-band maximum.