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

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.