IBS 이차원양자헤테로구조체연구단에서 University of Cambridge의 Manish Chhowalla교수님을 초청하여 아래와 같이 세미나를 개최합니다.

학과 구성원 여러분의 많은 참여를 부탁드립니다.

○ Topic: Ultra-clean interfaces between 2D MoS2, contact metals, and high K dielectrics

○ Speaker: Prof. Manish Chhowalla (University of Cambridge, Materials Science & Metallurgy, Cambridge, UK)

○ Date/time: 2024. 9. 5(Thur) 4:30 PM

○ Place: Chemistry Building 330102

○ Abstract: The interface between two-dimensional transition metal dichalcogenide (2D TMDs) semiconductors and metal contacts has been extensively studied. Clean van der Waals contacts now allow both high quality n- and to lesser extent p-type contacts. In contrast, the 2D semiconductor/dielectric interface has not been as widely studied as the metal/2D TMD junction. Here I will summarise our work on contacts and provide new results on the 2TMD/dielectric interface. The dielectric for 2D TMD devices must be thermodynamically and mechanically stable as well as being chemically inert. The band offset between the conduction and valence bands of the dielectric and 2D semiconductor should be at least 1eV. The 2D TMD/dielectric interface should be clean and free of defects. In this presentation, we present detailed synchrotron XPS study of 2D TMD and oxide interface. Specifically, we have studied the band offsets between MoS2 and SiO2, HfO2, and ZrO2 using XPS. We find that the dielectrics strongly dope the 2D MoS2 with significant shift (>1eV) in the Fermi level. Our results provide insight into suitability of different dielectrics for 2D MoS2 FETs.