Engineering Hybridized Excitons in van der Waals Heterostructures

Abstract

Two-dimensional transition metal dichalcogenide (2D TMDCs) materials are being utilized as platforms for research in atomically thin optoelectronics, owing to their superior optical properties. In particular, due to their discrete band states and ease of vertical stacking, extensive research on band alignment has been conducted. Although there has been significant optical research on interlayer excitons formed by type II band alignment in vdW heterostructures, precise physical analysis has faced limitations due to weak photoresponse. However, research on hybridized excitons formed through the hybridization of interlayer and intralayer excitons via resonant tunneling of nearly degenerate conduction bands (CB) or valence bands (VB) can offer large photoresponse due to the intralayer component, enabling the study of various physical phenomena including the moiré superlattice effect. In this study, we utilized tunneling phenomena to excactly modulate the band alignment of heterojunctions and observed the formation and response of hybridized excitons both electrically and optically. We demonstrated that the type and quantity of hybridized excitons can be controlled by the direction and magnitude of the voltage inducing resonant tunneling. This research presents a novel platform to quantitative study of interlayer and intralayer exction hybridization via resonant tunneling.