Defect-Engineered Magnetic Field Dependent Optoelectronics of Vanadium Doped Tungsten Diselenide Monolayers

摘要

The ability to dope transition metal dichalcogenides such as tungsten diselenide(WSe_2) with magnetic transition metal atoms in a controlled mannerhas motivated intense research with the aim of generating dilute magneticsemiconductors. In this work, semiconducting WSe_2 monolayers, substitutionallydoped with vanadium atoms, are investigated using low-temperatureluminescence and optoelectronic spectroscopy. V-dopants lead to a p-typedoping character and an impurity-related emission ≈160 meV below the neutralexciton, both of which scale with the nominal percentage of V-dopants.Measurements using field-effect devices of 0.3% V-doped WSe_2 demonstratebipolar carrier tunability. The doped monolayers display a clear magnetichysteresis in transport measurements both under illumination and withoutillumination, whereas the valley polarization of the excitons reveals anonlinear g-factor without a magnetic hysteresis within the experimentaluncertainty. Hence, this work on V-doped WSe_2 provides crucial insights concerningsuitable characterization methods on magnetic properties of doped2D materials.