B-Ga2O3 for next-generation devices: exploring anisotropic properties and p-type doping

Zeyu CHI

Post-doc

Groupe d’étude de la matière condensée, CNRS, UVSQ, Université Paris Saclay

β-Ga2O3 for next-generation devices: exploring anisotropic properties and p-type doping

Abstract

Improving energy efficiency and reducing power consumption is important for accelerating climate saving. To this end, ultra-wide bandgap (UWBG) semiconductors such as β-Ga₂O₃, with an UWBG of approximately 4.8 eV, offer a promising outlook for high-voltage power electronics (>10 kV) and solar-blind (UVC) photodetectors. To unlock the full potential of this material and facilitate advanced power devices, achieving “bipolar” conduction (both n and p-type) is crucial.

While n-type doping in the range of 10^16-20 cm^-3 has already been successfully controlled, the p-type doping remains a significant challenge for the scientific community. Moreover, the monoclinic structure of β-Ga₂O₃ exhibits strong crystallographic anisotropy, resulting in notable variations in structural and electrical properties depending on the crystallographic orientations of the planes.

In this seminar, I will present an overview of recent progress of my works, demonstrating the pronounced dependence of structural and electrical properties on crystal orientation of β-Ga₂O₃, the deep acceptor and auto-compensation effects arising from zinc doping during MOCVD growth, and the effective p-type doping via phosphorous implantation.

Short Bio/CV
Zeyu Chi received his PhD in Physics from Université Paris Saclay in 2023. He continued his research on the same topic as a post-doc in the Groupe d’Etude de la Matière Condensée (GEMaC), CNRS. Since his PhD studies to present, his work has focused on the ultra-wide band gap semiconductor β-Ga₂O₃, particularly investigating the electronic properties of the thin layers grown by MOCVD, with the objective exploring and developing β-Ga₂O₃ based p-n diode.