# Raman and photoluminescence characterization of β-Ga2O3 for power electronic application

Enora Vuillermet, Camille Sonneville, Changzi Lu, Pierre Brosselard, Jean-Marie Bluet, Dominique Planson

<figure><img src="image_1.png" /></figure>

To cite this version:

Enora Vuillermet, Camille Sonneville, Changzi Lu, Pierre Brosselard, Jean-Marie Bluet, et al. Raman and photoluminescence characterization of β-Ga2O3 for power electronic application. WORKSHOP ON GALLIUM OXIDE AND RELATED MATERIALS, Sep 2025, Grenoble, France. hal-05317962

HAL Id: hal-05317962

https://hal.science/hal-05317962v1

Submitted on 17 Oct 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Raman and photoluminescence characterization of β-Ga₂O₃ for power electronic application

Enora Vuillermet¹, Changzi Lu¹,², Camille Sonneville¹

Pierre Brosselard¹, Jean-Marie Bluet² and Dominique Planson¹

¹ INSA Lyon, Université Claude Bernard Lyon 1, Ecole Centrale de Lyon, CNRS, Ampère, UMR5005, 69621, Villeurbanne, France

² INSA Lyon, Université Claude Bernard Lyon 1, Ecole Centrale de Lyon, École supérieure de Chimie Physique Electronique de Lyon, CNRS, Institut des Nanotechnologies de Lyon, UMR 5270, 69621, Villeurbanne, France

The ultra-wide bandgap (Eg ~ 4,5 eV), high breakdown field (up to 8 MV/cm) [1], and short absorption edge of β-Ga₂O₃ have raised strong interest for high-voltage and low-loss power electronics, as a complement or potential alternative to wide-bandgap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN). Despite recent progress in bulk and epitaxial growth [2], the effects of doping and growth conditions on the structural and optical properties of β-Ga₂O₃ are still not fully understood. Identification and spatial distribution of defects such as, dislocations, doping impurities, or point defects, are also still a subject of discussion in recent publications [3,4].

The objective of this work is to better understand the impact of material defects and substrate orientation on β-Ga₂O₃ power devices performance. To this end, μ-Raman and photoluminescence (PL) measurements were realized respectively under green (532nm) and UV (325nm) laser excitation, to investigate the crystallinity and defects of β-Ga₂O₃ single crystals and epitaxial layers. While doping has little impact on the Raman spectra, the low symmetry of β-Ga₂O₃ monoclinic lattice leads to variations in Raman peaks depending on substrate orientation. Raman mappings show small shifts in peak position at the border of the samples, indicating minor stress variations and overall good crystalline quality of the samples. On the other side, PL measurements allow the identification and localization of point defects that are not visible by Raman spectroscopy. Furthermore, PL mappings show inhomogeneous defect distribution within the Fe-doped β-Ga₂O₃ substrate, both laterally and in depth (Fig.1), which could impact the performance of β-Ga₂O₃ power devices.

[1] M. Higashiwaki, *AAPPS Bull.* **32**, 3 (2022)

[2] S. Sun et al, *Adv. Electron. Mater.* **11**, 2300844 (2025)

[3] C. Remple et al, *AIP Adv.* **11**, 105006 (2021)

[4] A. Shokri et al, *ACS Omega.* **8**, 43732 (2023)

<figure><img src="image_3.png" /><figcaption>Figure 1. (a) Raman and PL spectra at the center of the Fe-doped β-Ga₂O₃ sample under respective laser excitation of 532 and 325nm. (b) Raman mapping of the Ag³ band position at 532nm and (c) PL mapping of the defect band position at 325nm of a Fe-doped β-Ga₂O₃ sample.</figcaption></figure>