On the electronic and spin-valley coupling of vanadium doped MoS 2(1-x) Se 2x monolayers.

Monolayers of MoS2 with tunable bandgap and valley positions are highly demanding for their applications in opto-spintronics. Herein, selenium (Se) and vanadium (V) co-doped MoS2 monolayers (vanadium doped MoS2(1-x)Se2x (V-MoSSe)) are developed and showed their variations in the electronic and optical properties with dopant content. Vanadium gets substitutionally (in place of Mo) doped within the MoS2 lattice while selenium doped in place of sulfur, as shown by a detailed microstructure and spectroscopy analyses. The bandgap tunability with selenium doping can be achieved while valley shift is occurred due to the doping of vanadium. Chemical vapor deposition assisted grown MoS2 (also selenium doped MoS2 as shown here) is known for its n-type transport behaviour while vanadium doping is found to be changing its nature to p-doping. Chirality dependent photoexcitation studies indicate a room temperature valley splitting in V-MoSSe (~8 meV), where such a valley splitting is verified using density functional theory based calculations.