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HL: Fachverband Halbleiterphysik
HL 36: Poster III
HL 36.10: Poster
Wednesday, March 20, 2024, 18:00–20:30, Poster E
Enhanced room-temperature spin-valley coupling in Vanadium-doped MoS2 — •Krishna Rani Sahoo1,2, Janmey Jay Panda1, Sumit Bawari1, Rahul Sharma1, Dipak Maity1, Ashique Lal1, Raul Arenal3, G Rajalaksmi1, and Tharangattu N. Narayanan1 — 1Tata Institute of Fundamental Research-Hyderabad, Sy. No. 36/P, Gopanapally Village, Serilingampally Mandal, Hyderabad-500046, India — 2Institute of Physics, University of Münster, Wilhelm-Klemm-Straße 10 48149 Münster, Germany — 3Fundación ARAID, 50018 Zaragoza, Spain
Achieving room-temperature valley polarization in atomically thin materials by substitutional doping opens new avenues of spintronic applications. Here, we demonstrate that monolayer MoS2 (MS) doped with vanadium (V) at low concentrations exhibits high spin-valley coupling and hence a high degree of valley polarization at room temperature. A time-reversal symmetry broken energy shift in the equivalent valleys is predicted in V-doped MoS2 (VMS). Our room-temperature chirality-controlled photoluminescence excitation measurements indicate such a shift in valley exciton energies (~35 meV). An enhanced valley polarization in VMS (~42%) is observed in comparison to that in MS (<12%), while in MS, the chirality-controlled excitations did not show a difference in emission energies. Spin Hall effect of light-based optical rotation measurements indicate the asymmetric absorption among the two different chiralities of the incident light, hence supporting the existence of room-temperature valley polarization.
Keywords: Doping; 2D material; valley polarization; photoluminescence; Spin hall effect