Bandgap modulation in self-limited two-dimensional Ga2O3 films via defect engineering

M Moyu Wei (State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,) Y Yunkai Li Y Yicheng Pei (State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,) Y Yuyang Wang (State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University) H Hanyu Zhao (State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,) C Chenlin Ai (State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,) H Han Kong (State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,) G Guoguo Yan (State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,) X Xingfang Liu

Abstract

We demonstrated the controllable exfoliation of two-dimensional gallium oxide (2D-Ga2O3) thin films via a touch printing process that leverages the self-limiting oxidation behavior of liquid gallium. The resulting films exhibited high thickness uniformity and surface smoothness. After annealing at 800 °C for 1 h, the film thickness was reduced from 6.8 to 3.9 nm due to recrystallization. Furthermore, by precisely modulating the annealing parameters, we introduced point defects and promoted the formation of a Ga–Si–O solid solution, enabling continuous bandgap tunability within the range of 4.88–7.22 eV. This work establishes a clear correlation among annealing, defect evolution, and band structure modulation.

Article Details

Volume / Issue Vol. 128, Issue 6
Published February 09, 2026
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (9)

M

Moyu Wei

State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,

Y

Yunkai Li

Y

Yicheng Pei

State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,

Y

Yuyang Wang

State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University

H

Hanyu Zhao

State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,

C

Chenlin Ai

State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,

H

Han Kong

State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,

G

Guoguo Yan

State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,

X

Xingfang Liu