Trapping the carrier in the spin-locked MoS2 atomic valley by absorption of chiral L-cysteine

This work demonstrates enhanced valley contrasting spin-momentum locked chiral states at the van der Waals interface of chiral L-cysteine and single layer (SL) MoS2 placed on a Si/SiO2 substrate at ambient conditions. Helicity dependent photoluminescence and resonance Raman measurements highlight spin-locked transitions for the chiral L-cysteine modified SL-MoS2 at ambient conditions. Selective adsorption of chiral L-cysteine dimer/cysteine stabilizes the in-plane effective magnetic field due to the Si/SiO2 substrate and blocks the intervalley spin relaxation. The observed polarization efficiency can be useful for improving the functionality of valley-based light emitting diodes and encoding information in logical devices.