HOT CARRIER OPTOELECTRONIC PHENOMENA IN VAN DER WAALS HETEROSTRUCTURES

Abstract

Two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs) exhibit strong light-matter coupling and ultrafast charge transfer across their van der Waals (vdW) interfaces which render TMDs as promising materials for hot-carrier optoelectronics. Photocarrier dynamics in vdW heterostructures depend on factors such as many-body effects and interface states which have been largely unexplored. This thesis investigates the photocarrier dynamics within TMD-based metal-insulator-semiconductor (MIS) vdW heterostructure and explores its potential optoelectronic applications. First, this thesis examines the electrical control of interlayer photocarrier transfer dynamics in MIS heterostructure and demonstrates its potential application as near-infrared to visible light electro-optic upconverters. Next, this thesis investigates the modulation of many-body effects in monolayer TMDs via encapsulation with 2D insulators. Lastly, this thesis reports the unusually robust photocurrent generation within the MIS heterostructure devices and demonstrates its origin from the interlayer transfer of hot carriers originating from efficient many-body effects within the 2D semiconducting TMD layer.