Structural, Electronic and Magnetic Properties of Vanadium Doped Transition Metal Dichalcogenides (TMDs)

Author

Qudsia Ashraf, The Graduate Center, City University of New YorkFollow

Date of Degree

9-2024

Document Type

Thesis

Degree Name

M.S.

Program

Nanoscience

Advisor

Maya Narayanan Nair

Committee Members

Gabriele Grosso

Tai-De Li

Subject Categories

Atomic, Molecular and Optical Physics | Inorganic Chemistry | Materials Chemistry | Other Physics

Keywords

Semiconductor, Transition metal, Doping, Magnetism, Holes, Spintronics

Abstract

Magnetic semiconductors are a prerequisite for spintronic devices but their ferromagnetism disappears at room-temperature hindering application in room temperature electronic devices. Enormous research has been conducted on the room-temperature ferromagnetic order in monolayer form of bulk van der Waals materials but the few layer system has not been extensively explored.

Doping is an effective approach to modulate the structural, electronic and magnetic properties of two-dimensional (2D) Transition metal dichalcogenides (TMDs) and expand their application. The effect of vanadium dopant on structural, electronic and magnetic properties of Tungsten Diselenide (WSe₂) was studied by X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), Magnetic Force Microscopy (MFM), Raman analysis, Energy-dispersive X-ray spectroscopy (EDX) and nitrogen-vacancy (NV) magnetometry.

The substitutional doping of vanadium atom into WSe₂ lattice leads to construction of p-type TMD semiconductor. The successful doping of vanadium atoms in WSe₂ bulk crystal and the p-type nature of the V-doped WSe₂ crystal has been confirmed by XPS. The Raman analysis exhibited red-shift and verified the p-doping effect of vanadium dopant on WSe₂.

The room-temperature ferromagnetic domains in few-layer V-doped WSe₂ have been demonstrated via magnetic force microscopy (MFM). Hence, incorporation of magnetic dopant is a promising approach for fabrication of spintronic devices without applying an external magnetic field.

Vanadium dopant atoms simultaneously endow TMDs with holes and magnetism and broaden their technological applications by creating a p-type air-stable room temperature 2D few layer magnet.

Recommended Citation

Ashraf, Qudsia, "Structural, Electronic and Magnetic Properties of Vanadium Doped Transition Metal Dichalcogenides (TMDs)" (2024). CUNY Academic Works.
https://academicworks.cuny.edu/gc_etds/5996