Split Ga vacancies: Abundant defects in β-Ga2O3

Filip Tuomisto; Antti Karjalainen; Ilja Makkonen

doi:10.1117/12.2585462

Split Ga vacancies: Abundant defects in β-Ga₂O₃

Filip Tuomisto^*, Antti Karjalainen, Ilja Makkonen

^*Corresponding author for this work

Department of Applied Physics

University of Helsinki

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

2 Citations (Scopus)

116 Downloads (Pure)

Abstract

We have applied positron annihilation spectroscopy to study a wide range of β-Ga₂O₃bulk crystals and thin films with various doping levels. The Doppler broadening of the 511 keV positron-electron annihilation line exhibits colossal anisotropy compared to other three-dimensional crystalline semiconductors. State-of-the-art theoretical calculations of the positron characteristics in the β-Ga₂O₃lattice reveal that the positron state is effectively 1-dimensional, giving rise to strong anisotropy. Strongly relaxed split Ga vacancies are found to exhibit even stronger anisotropy and to dominate the positron annihilation signals in almost all experiments. The evidence leads to the conclusion that split Ga vacancies are abundant, with concentration of 1018 cm-3 or more, in β-Ga₂O₃samples irrespective of conductivity.

Original language	English
Title of host publication	Oxide-Based Materials and Devices XII
Editors	David J. Rogers, David C. Look, Ferechteh H. Teherani
Publisher	SPIE
ISBN (Electronic)	9781510642096
DOIs	https://doi.org/10.1117/12.2585462
Publication status	Published - 2021
MoE publication type	A4 Conference publication
Event	Oxide-Based Materials and Devices - Virtual, Online, United States Duration: 6 Mar 2021 → 11 Mar 2021 Conference number: 12

Publication series

Name	Proceedings of SPIE - The International Society for Optical Engineering
Publisher	SPIE
Volume	11687
ISSN (Print)	0277-786X
ISSN (Electronic)	1996-756X

Conference

Conference	Oxide-Based Materials and Devices
Country/Territory	United States
City	Virtual, Online
Period	06/03/2021 → 11/03/2021

Keywords

Compensation
Defect
Gallium oxide
positron annihilation spectroscopy
Vacancy

Access to Document

10.1117/12.2585462

1168709Final published version, 851 KB

Cite this

@inproceedings{d1ae42676ef6421485ee3562f044dcce,

title = "Split Ga vacancies: Abundant defects in β-Ga2O3",

abstract = "We have applied positron annihilation spectroscopy to study a wide range of β-Ga2O3bulk crystals and thin films with various doping levels. The Doppler broadening of the 511 keV positron-electron annihilation line exhibits colossal anisotropy compared to other three-dimensional crystalline semiconductors. State-of-the-art theoretical calculations of the positron characteristics in the β-Ga2O3lattice reveal that the positron state is effectively 1-dimensional, giving rise to strong anisotropy. Strongly relaxed split Ga vacancies are found to exhibit even stronger anisotropy and to dominate the positron annihilation signals in almost all experiments. The evidence leads to the conclusion that split Ga vacancies are abundant, with concentration of 1018 cm-3 or more, in β-Ga2O3samples irrespective of conductivity.",

keywords = "Compensation, Defect, Gallium oxide, positron annihilation spectroscopy, Vacancy",

author = "Filip Tuomisto and Antti Karjalainen and Ilja Makkonen",

year = "2021",

doi = "10.1117/12.2585462",

language = "English",

series = "Proceedings of SPIE - The International Society for Optical Engineering",

publisher = "SPIE",

editor = "Rogers, {David J.} and Look, {David C.} and Teherani, {Ferechteh H.}",

booktitle = "Oxide-Based Materials and Devices XII",

address = "United States",

}

Tuomisto, F, Karjalainen, A & Makkonen, I 2021, Split Ga vacancies: Abundant defects in β-Ga₂O₃. in DJ Rogers, DC Look & FH Teherani (eds), Oxide-Based Materials and Devices XII., 2585462, Proceedings of SPIE - The International Society for Optical Engineering, vol. 11687, SPIE, Oxide-Based Materials and Devices, Virtual, Online, United States, 06/03/2021. https://doi.org/10.1117/12.2585462

Split Ga vacancies: Abundant defects in β-Ga₂O₃. / Tuomisto, Filip; Karjalainen, Antti; Makkonen, Ilja.
Oxide-Based Materials and Devices XII. ed. / David J. Rogers; David C. Look; Ferechteh H. Teherani. SPIE, 2021. 2585462 (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 11687).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

TY - GEN

T1 - Split Ga vacancies

T2 - Oxide-Based Materials and Devices

AU - Tuomisto, Filip

AU - Karjalainen, Antti

AU - Makkonen, Ilja

N1 - Conference code: 12

PY - 2021

Y1 - 2021

N2 - We have applied positron annihilation spectroscopy to study a wide range of β-Ga2O3bulk crystals and thin films with various doping levels. The Doppler broadening of the 511 keV positron-electron annihilation line exhibits colossal anisotropy compared to other three-dimensional crystalline semiconductors. State-of-the-art theoretical calculations of the positron characteristics in the β-Ga2O3lattice reveal that the positron state is effectively 1-dimensional, giving rise to strong anisotropy. Strongly relaxed split Ga vacancies are found to exhibit even stronger anisotropy and to dominate the positron annihilation signals in almost all experiments. The evidence leads to the conclusion that split Ga vacancies are abundant, with concentration of 1018 cm-3 or more, in β-Ga2O3samples irrespective of conductivity.

AB - We have applied positron annihilation spectroscopy to study a wide range of β-Ga2O3bulk crystals and thin films with various doping levels. The Doppler broadening of the 511 keV positron-electron annihilation line exhibits colossal anisotropy compared to other three-dimensional crystalline semiconductors. State-of-the-art theoretical calculations of the positron characteristics in the β-Ga2O3lattice reveal that the positron state is effectively 1-dimensional, giving rise to strong anisotropy. Strongly relaxed split Ga vacancies are found to exhibit even stronger anisotropy and to dominate the positron annihilation signals in almost all experiments. The evidence leads to the conclusion that split Ga vacancies are abundant, with concentration of 1018 cm-3 or more, in β-Ga2O3samples irrespective of conductivity.

KW - Compensation

KW - Defect

KW - Gallium oxide

KW - positron annihilation spectroscopy

KW - Vacancy

UR - http://www.scopus.com/inward/record.url?scp=85107176918&partnerID=8YFLogxK

U2 - 10.1117/12.2585462

DO - 10.1117/12.2585462

M3 - Conference article in proceedings

AN - SCOPUS:85107176918

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Oxide-Based Materials and Devices XII

A2 - Rogers, David J.

A2 - Look, David C.

A2 - Teherani, Ferechteh H.

PB - SPIE

Y2 - 6 March 2021 through 11 March 2021

ER -