时间: 2025年7月18日（周五）下午14:00-15:30

Time: 14:00-15:30, Friday, July 18, 2025

主持人: 西湖大学理学院PI 王乃舟 博士

Host: Dr. Naizhou Wang, PI of School of Science, Westlake University

地址：云谷校区E10-215教室

Venue: E10-215, Yungu Campus

讲座语言：中文

Lecture Language: Chinese

赖屾 助理教授

澳门大学

Shen Lai

Assistant Professor, University of Macau

主讲人/Speaker:

Prof. Shen LAI achieved his Ph.D. degree in Nano Engineering from Sungkyunkwan University, Korea in 2018 and he worked as a research fellow at Nanyang Technological University, Singapore, from 2018 to 2022. He is currently an assistant professor in Institute of Applied Physics and Materials Engineering, University of Macau in Macau, China. He has published more than 30 articles in the field of 2D materials transport properties and devices.

讲座摘要/Abstract:

Developing van der Waals (vdW) high-k dielectric layers is a key factor in achieving high-performance two-dimensional (2D) semiconductor field effect transistors (FETs). Here, we experimentally reveal that layered GaPS₄ flakes exhibit a high dielectric constant of up to 35 and a high capacitance density (~2.95μF/cm²), along with a bandgap larger than 4.15eV. Band alignment of MoS₂/GaPS₄ heterostructure indicates a unipolar-like barrier between MoS₂ and GaPS₄ for electrons of ~1.92 eV. We employed GaPS₄ as gate dielectric with an equivalent oxide thickness (EOT) of 1 nm in a MoS₂ FET, and the device shows a low gate leakage current of 10^-13A, a high on/off ratio of ~3×10⁸, and minimal hysteresis (~20mV). Theoretical modeling confirms that weak interactions preserve the MoS₂ channel’s inherent electronic properties. Compared to other layered dielectrics, GaPS₄ in MoS₂ FETs demonstrates superior properties in terms of bandgap, dielectric constant, EOT and on/off ratio. These advantages highlight the potential of GaPS₄ for integration into 2D semiconductor FETs.

讲座联系人/Contact:

School of Science, Shaowei Ma, Email: mashaowei@westlake.edu.cn