Fig. 1. MoS₂/WSe₂ heterobilayer-PhCC nanolaser.

(A) 3D schematic image of the fabricated heterobilayer-PhCC nanolaser. (B) First panel: Optical microscope image of MoS₂/WSe₂ heterobilayer on silicon PhCC. The MoS₂ monolayers, WSe₂ monolayers, and PhCC are indicated by the red, blue, and black dashed lines, respectively. Second panel: Top-view scanning electron micrograph around the defect region of the L3-type defect silicon PhCC. The arrows show the displacement of the two end-holes by 0.163a (48.4 nm). The radius of other gray holes is shrunk to be ~62.4 nm to enhance the far-field vertical coupling. Third and fourth panels: Optical microscope image of WSe₂ and MoS₂ monolayers on PDMS before transfer, respectively. (C) Interlayer excitonic emission in MoS₂/WSe₂ heterobilayer compared with the intralayer emission in the two constituents. The spectra of monolayers were measured at room temperature with an excitation of 532 nm, and the spectrum of heterobilayer was measured at 5 K with an excitation of 740 nm. a.u., arbitrary units. (D) Cavity lasing mode emission spectrum taken at a continuous-wave pump power of 190 μW (T = 5 K). Lasing action occurs at λ = 1122.5 nm with a measured linewidth of ~2.7 nm.