Electrical modulation of excitonic transition in monolayer tungsten disulfide on periodically poled ferroelectric substrates

Abstract

Although the spectral investigation of monolayer two-dimensional transition metal dichalcogenide (1L-TMD) has been extensively performed for identifying modulation of excitonic transition, study of excitonic transition in ferroelectric/TMD hybrid structure is essential to understand and design high speed and low loss devices based on in-plane junctions. Here, we demonstrate electrical modulation of excitonic transition by transferring 1L-tungsten disulfide (WS2) onto a ferroelectric domain surface, a periodically poled lithium niobate (PPLN). We observe that exciton (A0) and trion (A-) emissions of 1L-WS2 are spatially modulated depending on the sign of the phase domain, such that A0 and A- emission is stronger at the positive (D+) and negative (D-) domain, respectively. In addition, different trends of excitonic transition of 1L-WS2 between D+ and D- domain are demonstrated by applying a back-gate bias voltage. The spatial modulation of electrical and optical characteristics of 1L-TMDs will help to design the homo- or hetero p-n junctions based on TMDs.