Valley Engineering of Monolayer MoS2 via Substitutional Cr and V Dopants and the Mechanistic Insights
Sreekant Anil, Dipak Maity, Snehith Adabala, Arpan De, Nagendra S. Kamath, Raheel Hammad, Janmey Jay Panda, Ravi K. Biroju, Viliam Vretenar, Rajalakshmi G, Suman Kalyan Pal, Soumya Ghosh, and Tharangattu N. Narayanan
In: Nano Lett. 2025
https://doi.org/10.1021/acs.nanolett.5c03877
Abstract:
MoS2 monolayers (MS) having magnetic impurities as dopants can bring about time-reversal asymmetry and hence room temperature magnetism. Here, we demonstrated the synthesis of Cr substitutionally doped (∼1%) MS (CrMS) along with its vanadium-doped MS counterpart (VMS) and investigated their suitability for valleytronics by studies based on chirality-selective photoluminescence, time-resolved transient absorption spectroscopy, and spin Hall effect of light (SHEL). While VMS showed room temperature valley splitting, no such shift was observed in CrMS although with their expected similarity. Density-functional-theory-based electronic structure calculations indicate a Cr-induced flat band below the Fermi level, even at ∼0.5 atom % doping, which masks the splitting in the energies of the K-point valleys. This finding is in tune with the experimental studies while in contrast to the theoretical and experimental data of VMS. Hence, this study establishes band valley tunabilities of MoS2, and SHEL as a powerful tool for valley polarization studies.