Biography
Prof. Jiyan Dai
Prof. Jiyan Dai
Department of Applied Physics, The Hong Kong Polytechnic University
Title: Electrical and thermoelectric properties of ZrTe2 thin films
Abstract: 
Achieving high thermoelectric power factor in thin film heterostructures is essential for integrated and miniatured thermoelectric device applications. In this work, we demonstrate a mechanism and device performance of enhanced thermoelectric power factor induced by interfacial confined two-dimensional electron gas (2DEG) in a transition metal dichalcogenides-SrTiO3 (STO) heterostructure. Owing to the formed conductive interface with two-dimensional electron confinement effect and the elevated conductivity, the ZrTe2/STO heterostructure presents enormous thermoelectric power factor as high as  at 10K. Formation of quasi-two-dimensional electrons gas at the interface is attributed to the giant Seebeck coefficient and high electrical conductivity, leading to extremely large thermoelectric power factor. This high thermoelectric power factor is demonstrated by a prototype device based on this heterostructure which results in 3K temperature cooling by passing through a current of 100 mA. This superior thermoelectric property makes this heterostructure a promising candidate for future thermoelectric device. We also observed room-temperature anomalous hall effect in the heterostructure of YIG/ZrTe2.
Biography: 
Dai Jiyan is currently a Professor of the Department of Applied Physics at The Hong Kong Polytechnic University. He received his B.Sc. degree in physics from Fudan University in 1988, his M.S. degree in Electronic Engineering from Tsinghua University in 1991, and his Ph.D. degree in Materials Physics from the Chinese Academy of Sciences in 1994. He has postdoctoral research experience at Northwestern University, Prof. Dai’s research interests include ferroelectric and multiferroic oxide and telluride thin films and their heterostructures and devices. His most recent works focus on thin film flexoelectric effect and modulation to thin film transport properties. He has published over 200 journal papers with citation more than 10000 times. He has written a monograph book “Ferroic materials in smart systems-from fundamentals to device applications”, 2020 Wiley.