Fig. 1

Excitonic states of TMDs-based trilayer heterostructure, interlayer excitons model, and computed band structure and wavefunction distribution comparisons between the bilayer and trilayer heterostructures. a Illustration of WSe₂–MoSe₂–WSe₂ trilayer heterostructure with a sandwiched single layer (SL) MoSe₂ between two SLs WSe₂. b Schematic summary of the interlayer exciton radiative recombination predicted by type-II heterojunction. ε_X, ε_opt, and ε_g represent the exciton binding energy, optical gap, and electronic gap, respectively. c Computed band structure of the WSe₂–MoSe₂ bilayer heterostructure. d Computed band structure of the WSe₂–MoSe₂–WSe₂ trilayer heterostructure. e Computed orbital wavefunction of the WSe₂–MoSe₂ bilayer heterostructure valence band maximum (VBM) and conduction band minimum (CBM) at k-point as a function of the interlayer distance z. f Computed orbital wavefunction of the WSe₂–MoSe₂–WSe₂ trilayer heterostructure