Molecular beam epitaxy of ferroelectric ScAlN on <b> <i>β</i> </b> -Ga2O3 substrates

Y Yuzhi Deng (College of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University 1 , Beijing 100096,) R Rui Wang H Haotian Ye X Xiaoyang Yin R Ran Feng (Department of Geosciences) B Bingxuan An B Baocong Huang (College of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University 1 , Beijing 100096,) X Xiantong Zheng (College of Instrument Science and Opto‐electronics Engineering Beijing Information Science and Technology University Beijing 100096 China) T Tao Wang W Wenxiang Mu (State Key Laboratory of Crystal Materials, Institute of Novel Semiconductors, Institute of Crystal Materials, Shandong University 5 , Jinan, Shandong 250100,) D Ding Wang F Fang Liu Y Yi Tong Y Yulin Feng (College of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University 1 , Beijing 100096,) Y Yuan Liu B Bo Shen (Department of Chemistry) P Ping Wang X Xinqiang Wang (Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology)

Abstract

We demonstrate the epitaxial integration of ferroelectric ScAlN thin films on β-Ga2O3 substrates via molecular beam epitaxy without any buffer layers, enabled by surface pre-nitridation. The resulting ScAlN films exhibit robust ferroelectricity, characterized by large apparent remanent polarization (&amp;gt;150 μC/cm2), good retention (&amp;gt;105 s), and minimal fatigue observed up to 105 switching cycles. High-resolution x-ray photoelectron spectroscopy reveals a type-II band alignment at the ScAlN/β-Ga2O3 heterointerface, with extracted valence and conduction band offsets of 0.5 and 1.0 eV, respectively. These results establish an oxide/nitride heterostructure platform that combines the intrinsic ferroelectricity of ScAlN with the ultra-wide bandgap and photosensitive properties of β-Ga2O3, offering compelling opportunities for next-generation nonvolatile memory, photodetection, and optoelectronic synaptic devices.

Article Details

Volume / Issue Vol. 128, Issue 18
Published May 04, 2026
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (18)

Y

Yuzhi Deng

College of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University 1 , Beijing 100096,

R

Rui Wang

H

Haotian Ye

X

Xiaoyang Yin

R

Ran Feng

Department of Geosciences

B

Bingxuan An

B

Baocong Huang

College of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University 1 , Beijing 100096,

X

Xiantong Zheng

College of Instrument Science and Opto‐electronics Engineering Beijing Information Science and Technology University Beijing 100096 China

T

Tao Wang

W

Wenxiang Mu

State Key Laboratory of Crystal Materials, Institute of Novel Semiconductors, Institute of Crystal Materials, Shandong University 5 , Jinan, Shandong 250100,

D

Ding Wang

F

Fang Liu

Y

Yi Tong

Y

Yulin Feng

College of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University 1 , Beijing 100096,

Y

Yuan Liu

B

Bo Shen

Department of Chemistry

P

Ping Wang

X

Xinqiang Wang

Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology