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Abstract Scalable substitutional doping of 2D transition metal dichalcogenides is a prerequisite to developing next‐generation logic and memory devices based on 2D materials. To date, doping efforts are still nascent. Here, scalable growth and vanadium (V) doping of 2D WSe2at front‐end‐of‐line and back‐end‐of‐line compatible temperatures of 800 and 400 °C, respectively, is reported. A combination of experimental and theoretical studies confirm that vanadium atoms substitutionally replace tungsten in WSe2, which results inp‐type doping via the introduction of discrete defect levels that lie close to the valence band maxima. Thep‐type nature of the V dopants is further verified by constructed field‐effect transistors, where hole conduction becomes dominant with increasing vanadium concentration. Hence, this study presents a method to precisely control the density of intentionally introduced impurities, which is indispensable in the production of electronic‐grade wafer‐scale extrinsic 2D semiconductors.
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Room‐Temperature Ferromagnetism in MoTe 2 by Post‐Growth Incorporation of Vanadium Impurities
Abstract Post‐synthesis doping of 2D materials is demonstrated by incorporation of vapor‐deposited transition metals into a MoTe2lattice. Using this approach, vanadium doping of 2H‐MoTe2produces a 2D ferromagnetic semiconductor with a Curie temperature above room temperature (RT). Surprisingly, ferromagnetic properties can be induced with very low vanadium concentrations, down to ≈0.2%. The vanadium species introduced at RT are metastable, and annealing to above ≈500 K results in the formation of a thermodynamically favored impurity configuration that, however, exhibits reduced ferromagnetic properties. Doping with titanium, instead of vanadium, shows a similar incorporation behavior, but no ferromagnetism is induced in MoTe2. This indicates that the type of impurities in addition to their atomic configuration is responsible for the induced magnetism. The interpretation of the experimental results is consistent with ab initio calculations, which confirm that the proposed vanadium impurity configurations exhibit magnetic moments, in contrast to the same configurations with titanium impurities. This study illustrates the possibility to induce ferromagnetic properties in layered van der Waals semiconductors by controlled magnetic impurity doping and thus to add magnetic functionalities to 2D materials.
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- PAR ID:
- 10461642
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Electronic Materials
- Volume:
- 5
- Issue:
- 5
- ISSN:
- 2199-160X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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