Fig. 4: Increasing IX dipole moment with the increasing WS2 layer number.
From: Observation of giant dipole moments of interlayer excitons via layer engineering
a Evolution of PL emission spectra of the 2L/6L HSs interface under an applied voltage. b Evolution of PL emission spectra of the 3L/6L HSs interface under the same applied voltage. c Electric field dependence of the interlayer exciton energies in 2L/6L and 3L/6L HSs. d, e Top and side views of exciton wave functions for 2L- and 3L-WS2. The fixed electron position is indicated by the black arrow. The inset in each side view is the exciton wave function density along the out-of-plane direction. Black dashed lines are electron positions. Red dashed lines are the equivalent center position of the wave function. f Comparison of performances of IXs in this work with those from other systems, including IXs in TMDCs and hybrid interlayer-intralayer excitons (hIXs) in TMDCs8,16,17,31,32,33,34,35, obtained experimentally in mL/nLHSs. Theoretically, the dipole moments and working wavelength regime in mL/nL HSs can be further extended by choosing different thickness combinations.
