Figure 5.

Schematic illustration of a possible recombination pathway of (a) semidark trions made optically active due to the e–e scattering and (b) negative biexcitons. The black dashed lines represent e–e scattering, which transfers an electron from the lower subband of the CB at the K^± point to the corresponding higher subband at the opposite K^∓ point. (c) Power dependence of the low-temperature PL spectra of the WS₂ ML. The intensities of the PL spectra are normalized by the X^B intensity. The inset displays the PL spectrum under 10 μW excitation due to the T^I, XX₁^–, and XX₂ lines deconvoluted using Lorentzian function. (d) The intensity evolution of the emission features with excitation power. The dashed black line indicates the linear and quadratic behaviors as a guide to the eye. (e) Transition energies of the σ^± (red/blue points) components of the T′, XX₁^–, and XX₂ lines as a function of the out-of-plane magnetic field. The solid lines represent fits according to the equation described in the text.