Fig. 1
From: Tuning the Fröhlich exciton-phonon scattering in monolayer MoS2
Valley polarization in dependence of the electron density. a Circularly polarized PL spectra for σ+ excitation and σ+ (co-polarized) and σ− (cross-polarized) detection measured with Ei = 1.96 eV and at T = 220 K for two different gate voltages of a 1L-MoS2 device with ionic liquid top gate. Spectra are normalized to the maximum of the respective co-polarized spectrum. The absolute intensity of the spectra for −2 V is a factor of 10 higher than for the spectra taken for 0 V. b Spectrally resolved degree of polarization for a series of gate voltages. Negative (positive) gate voltages correspond to electron depletion (accumulation). c Degree of polarization as a function of the applied top gate voltage of the total PL signal as shown in b evaluated at the PL peak maxima, and of the individual contributions of the neutral (A0) and charged (A−) exciton obtained from peak fits. The error bars denote the standard deviation from the fit approach
