【Epitaxy Papers】Evolution of structural and photoluminescent properties of sputter-deposited Ga₂O₃ thin films during post-deposition heat treatment

      Researchers from the HUN-REN Centre for Energy Research have published a dissertation titled "Evolution of structural and photoluminescent properties of sputter-deposited Ga₂O₃ thin films during post-deposition heat treatment" in Journal of Alloys and Compounds.

Abstract

      In situ spectroscopic ellipsometry and ex situ structural investigations were performed on annealed amorphous Ga₂O₃ thin films prepared by radio frequency sputtering. The change of the optical parameters was monitored during the annealing in air. In situ ellipsometry was shown to be a valuable method to determine the phase transition temperatures of Ga₂O₃ during annealing in ambient conditions. X-ray diffraction and transmission electron microscopy revealed that the initially amorphous film first crystallizes into the metastable γ-Ga₂O₃ phase, which transforms into the β-Ga₂O₃ phase at higher temperatures. Optical transmittance measurements were used to determine the optical bandgap of the layers at the different annealing steps. Photoluminescence experiments were performed on the samples after annealing at varying temperatures and atmospheres. After the initial formation of the γ-Ga₂O₃ phase a broad green luminescence band emerged, while after the transformation to the β-Ga₂O₃ phase blue or red emission was observed depending on the annealing atmosphere.

DOI：

https://doi.org/10.1016/j.jallcom.2025.179634