High-quality CVD Grown Monolayer Molybdenum Disulfide and Dry Transfer in Field-effect Transistors

High-quality CVD Grown Monolayer Molybdenum Disulfide and Dry Transfer in Field-effect Transistors
10:00
Room 4472 (Lifts 25-26), HKUST

Abstract

Two-dimensional semiconducting transition metal dichalcogenides (TMDC) have attracted many attentions for their interesting electronic and optoelectronic properties. Among all synthetic methods, chemical vapor deposition (CVD) has been the most promising technique to massively produce layered TMDC in industry. In this thesis, CVD growth was conducted and modified to synthesize high-quality monolayer molybdenum disulfide (MoS2), one of the most popular materials among TMDC, and corresponding field-effect transistors (FETs) were fabricated to examine its intrinsic electrical properties. Raman and photoluminescence spectroscopy confirmed the high quality of the as-grown monolayer MoS2. Sulfur vacancy repairing technique was developed with enhanced optical properties. All-dry transfer technique was introduced to construct FETs, showing ultra-clean interface in high-resolution transmission electron microscopy. The n-type channel of MoS2 monolayer can reach a field-effect mobility up to 250 cm2V-1s-1 and on/off ratio up to 108 at room temperature. Phonon scattering mechanism and magnetic response were investigated by using both Hall-bar and Corbino-like electrode geometries.

Speakers / Performers:
Mr. Pingge HE
Department of Physics, The Hong Kong University of Science and Technology
Language
English
Organizer
Department of Physics