Fig. 4.
Theoretical model and experimental data fitting. a Sample of the experimental data (temperature, T = 2.3 K) and the fitting to the theoretical model. The data is obtained using σ− polarized pulsed excitation and σ− polarized PL detection. Semi-log plot is used. b, c The two conversion pathways from the WSe2 dark exciton to the interlayer exciton. In the first pathway (A-B-D), the spin flip happens before the interlayer charge transfer while in the second one (A-C-D), the interlayer charge transfer happens before the spin flip. The conversion rate in the first path has an exponential magnetic field dependence while it is constant for the second path. d Scattering rate from dark exciton to interlayer exciton versus magnetic field. The dark-to-interlayer scattering rates in K valley (σ− PL) and K′ valley (σ+ PL) are plotted against magnetic field and fitted using exponential function