Polarity modulation in compositionally tunable Bi₂O₂Se thin films

Authors

Ying-Hao Chu ⋅ TW Department of Materials Science and Engineering, National Tsing Hua University

Abstract

Two-dimensional (2D) materials have emerged as one of the most promising candidates to meet the demands of beyond-silicon technology. Among 2D semiconductors, Bi₂O₂Se (BOSe) stands out as a channel material for advanced electronic applications, due to its high electron mobility and the formation of a native high-k dielectric layer. However, fabricating p-type 2D BOSe transistors remains challenging. Here, we report an area-selective doping method at low temperatures (~600 K, compatible with back-end-of-line processes) for pulsed laser-deposited BOSe thin films, enabling the modulation of their carrier polarity through the introduction of Zn²⁺ substitutional dopants. Taking advantage of this doping strategy, we demonstrate the fabrication of a 2D vertical p-n homojunction with an on/off ratio in photoresponse of ~6-order enhancement and planar transistors based on p-doped BOSe homojunctions. Our results help promote the application of this material system towards the development of the next-generation electronics.

About the Speaker

Ying-Hao Chu, Department of Materials Science and Engineering, National Tsing Hua University

Professor Ying-Hao CHU received his Ph.D. from the Department of Materials Science and Engineering at National Tsing Hua University in 2004. Then, he joined the University of California, Berkeley, as a postdoc. In 2008, he acquired an assistant professorship in the Department of Materials Science and Engineering at National Chiao Tung University. He was promoted to associate professor in 2015 and then to professor in 2018. In 2019, he was appointed as a distinguished professor. Since 2013, he had an adjunct position at the Institute of Physics, Academia Sinica. In 2014, he started an adjunct position in the Department of Electrophysics at National Chiao Tung University. From 2016 to 2018, he had an adjunct position in Material and Chemical Research Laboratories, Industrial Technology Research Institute, and the International College of Semiconductor Technology at National Chiao Tung University. In 2019, he had an appointment with ACS Applied Electronic Materials to be an associate editor. In 2025, he was promoted to executive editor. In 2022, he returned to National Tsing Hua University with a promotion in the summer to be a distinguished professor. From 2022 July to 2025 January, he was named the Center for Nanotechnology, Materials Science, and Microsystems Director at National Tsing Hua University. From 2024 May to 2025 January, he started his appointment as the Associate Vice President of Research and Development at National Tsing Hua University. He was promoted to chair professor in the summer of 2024. From 2022, he has joint appointments with the College of Semiconductor Research, National Tsing Hua University, Department of Materials Science and Engineering and Department of Electrophysics, National Yang Ming Chiao Tung University, and Institute of Physics, Academia Sinica. From 2025, he had an adjunct position in the Center for Nanotechnology, Materials Science, and Microsystems director at National Tsing Hua University. His research is highly focused on functional oxides and strongly correlated electron systems. He has extensive experience using advanced characterization techniques to understand and manipulate functional oxide heterostructures, nanostructures, and interfaces. He aims to create a pathway to use high-quality oxide heteroepitaxy for soft transparent technology. Now, he is a pioneer with the most publications in this research direction. He has published more than 390 papers in academic journals with more than 35 papers in the Science and Nature line of publications.

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Issue

2025: Proceedings of the 43rd Samahang Pisika ng Pilipinas Physics Conference

Article ID

SPP-2025-INV-PS-12

Section

Invited Presentations

Published

2025-06-24

How to Cite

[1]

Y-H Chu, Polarity modulation in compositionally tunable Bi2O2Se thin films, Proceedings of the Samahang Pisika ng Pilipinas 43, SPP-2025-INV-PS-12 (2025). URL: https://proceedings.spp-online.org/article/view/SPP-2025-INV-PS-12.