Fig. 1: Hybrid excitons in rotationally aligned WS2/MoSe2 bilayers.
From: Twist-angle dependence of moiré excitons in WS2/MoSe2 heterobilayers
a An optical microscope image of a hexagonal boron nitride (hBN)-capped heterobilayer. Red and blue solid lines outline the MoSe2 and WS2 monolayers, respectively. The inset is an atomistic model of the WS2/MoSe2 heterobilayer. Red and blue spheres represent MoSe2 and WS2 monolayers, respectively. The black solid diamond represents the moiré unite cell. b Top panels illustrate a unit cell of R-stacking (left) and H-stacking (right) WS2/MoSe2 bilayers. Middle panels depict the corresponding band alignment of WS2 and MoSe2, where X labels the intralayer transition and IX labels the nearly resonant interlayer transition that shares the same hole state. Solid and dashed lines correspond to states of opposite spins. Bottom panels illustrate the alignment between an intralayer MoSe2 A exciton state (red) and the interlayer exciton state (blue) that it hybridizes with. c Reflectance contrast (RC) spectra for, from bottom to top, a monolayer WS2 (blue), monolayer MoSe2 (red), R-stacking bilayer (orange), and H-stacking bilayer (purple). The dots are the data, and solid lines are fits. The spectra are displaced vertically for easier reading. d Summary of the fitted ratio of the oscillator strength between LHX and UHX, and the corresponding detuning δ.
