Journal Article

PUBDB-2022-06340

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Tackling Disorder in $γ$‐Ga$_2$O$_3$

Ratcliff, L. E. (Corresponding author) ; Oshima, T. ; Nippert, F. ; Janzen, B. M. ; Kluth, E. ; Goldhahn, R. ; Feneberg, M.Extern* ; Mazzolini, P. ; Bierwagen, O.Extern* ; Wouters, C. ; Nofal, M. ; Albrecht, M. ; Swallow, J. E. N.Extern* ; Jones, L. A. H. ; Thakur, P. K. ; Lee, T.-L.Extern* ; Kalha, C.Extern* ; Schlueter, C.DESY* ; Veal, T. D. ; Varley, J. B. ; Wagner, M. R. ; Regoutz, A.Extern*

2022
Wiley-VCH Weinheim

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Please use a persistent id in citations: doi:10.1002/adma.202204217  doi:10.3204/PUBDB-2022-06340

Abstract: Ga$_2$O$_3$ and its polymorphs are attracting increasing attention. The rich structural space of polymorphic oxide systems such as Ga$_2$O$_3$ offers potential for electronic structure engineering, which is of particular interest for a range of applications, such as power electronics. $γ$-Ga$_2$O$_3$ presents a particular challenge across synthesis, characterization, and theory due to its inherent disorder and resulting complex structure–electronic-structure relationship. Here, density functional theory is used in combination with a machine-learning approach to screen nearly one million potential structures, thereby developing a robust atomistic model of the $γ$-phase. Theoretical results are compared with surface and bulk sensitive soft and hard X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, spectroscopic ellipsometry, and photoluminescence excitation spectroscopy experiments representative of the occupied and unoccupied states of $γ$-Ga$_2$O$_3$. The first onset of strong absorption at room temperature is found at 5.1 eV from spectroscopic ellipsometry, which agrees well with the excitation maximum at 5.17 eV obtained by photoluminescence excitation spectroscopy, where the latter shifts to 5.33 eV at 5 K. This work presents a leap forward in the treatment of complex, disordered oxides and is a crucial step toward exploring how their electronic structure can be understood in terms of local coordination and overall structure.

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Contributing Institute(s):

1. DOOR-User (DOOR ; HAS-User)
2. PETRA-S (FS-PETRA-S)

Research Program(s):

1. 631 - Matter – Dynamics, Mechanisms and Control (POF4-631) (POF4-631)
2. 6G3 - PETRA III (DESY) (POF4-6G3) (POF4-6G3)

Experiment(s):

1. PETRA Beamline P22 (PETRA III)

Appears in the scientific report 2022

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; DEAL Wiley ; Essential Science Indicators ; IF >= 25 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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