Electronic structure modification in Fe-substituted β-Ga2O3 from resonant photoemission and soft x-ray absorption spectroscopies. (5th May 2022)

• Record Type: Journal Article
• Authors: Ghosh, Sahadeb; Nand, Mangla; Kamparath, Rajiv; Gupta, Mukul; Phase, D M; Jha, S N; Singh, S D; Ganguli, Tapas
• Is Part Of: Journal of physics. Volume 55:Number 18(2022)
• Publication Date: 2022-05-05
• Subjects: Ga2O3 -- resonant photoelectron spectroscopy -- x-ray absorption spectroscopy -- XRD -- thin film; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/ac43dc
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: Oriented thin films of β -(Ga1− x Fe x )2 O3 were deposited by radio frequency magnetron sputtering on c-Al2 O3 and GaN substrates. The itinerant character of the Fe 3d states forming the top of the valence band (VB) of the Fe-substituted β -Ga2 O3 thin films has been determined from resonant photoelectron spectroscopy. Further, the admixture of the itinerant and localized characters of these Fe 3d states has been obtained for larger binding energies; i.e. deeper in the VB. The bottom of the conduction band (CB) for β -(Ga1− x Fe x )2 O3 has been also found to have strongly hybridized states involving Fe 3d and O 2p states compared to that of Ga 4s in pristine β -Ga2 O3 . This suggests that β -Ga2 O3 transforms from a band-like system to a charge-transfer system with Fe substitution. Furthermore, the bandgap red shifts with Fe composition, which has been found to be primarily related to the shift of the CB edge.