Doping Techniques in Two-Dimensional Transition Metal Dichalcogenides

Doping techniques in two-dimensional transition metal dichalcogenides (TMDCs) aim to modulate carrier type and density, tailor band structures and unlock novel functionalities in atomically thin semiconductors. Strategies range from substitutional incorporation of foreign atoms during growth to post-synthesis treatments such as ion implantation, surface charge transfer and electrostatic gating. Substitutional doping can induce phase transformations, tune optical emission and shift the Fermi level to alter conductivity. Surface functionalisation by molecular adsorbates or alkali metal intercalation offers reversible control over carrier polarity, while codoping with complementary species enhances stability and mobility of p-type carriers. Recent efforts focus on achieving uniform and stable doping across wafer-scale monolayers, constructing lateral p–n homojunctions and integrating doped layers into logic circuits and photodetectors. These developments hold global significance for flexible electronics, optoelectronic sensing and scalable integrated circuits based on 2D TMDCs.

Research from Nature Portfolio

Recent studies have demonstrated degenerate substitutional doping of MoS₂ with niobium, triggering a structural transformation from the 2H to the 3R polytype. This phase change is accompanied by strong hybridisation between dopant states and host valence bands, non-linear modification of the electronic band structure and enhanced photoluminescence in monolayer MoS₂ through bound-exciton formation. Another work achieved dual incorporation of cobalt and chromium into a single MoS₂ monolayer, realising coexisting robust ferromagnetism and photoluminescence. By activating magnetic interactions via cobalt and suppressing non-radiative decay channels through chromium, both saturation magnetisation and emission intensity increase by orders of magnitude, paving the way for valleytronic and spintronic devices based on chalcogenide monolayers.

Doping Techniques in Two-Dimensional Transition Metal Dichalcogenides publication trend

The graph below shows the total number of articles in doping techniques in two-dimensional transition metal dichalcogenides across all publications each year (not limited to Nature Index journals).

Technical terms

Two-dimensional transition metal dichalcogenides (2D TMDCs): Layered materials of the form MX₂ (M = transition metal; X = chalcogen) with strong in-plane covalent bonding and weak interlayer van der Waals interactions, exhibiting tunable electronic and optical properties at monolayer thickness.

Substitutional doping: Introduction of foreign atoms into specific lattice sites of a host crystal to modulate its carrier concentration, electronic band structure and optical response.

Ion implantation: A technique that embeds dopant ions into a substrate by accelerating them to controlled kinetic energies, creating localised modifications without the need for high-temperature reactions.

Codoping: Simultaneous incorporation of two or more dopant species, often with complementary charge states or ionic radii, to enhance doping stability, carrier mobility or magnetic properties.

Lateral p–n homojunction: An in-plane interface within a single semiconductor layer, formed by adjacent regions of p-type and n-type doping, used to create rectifying junctions for diodes and photodetectors.

References

1. Reconfiguring crystal and electronic structures of MoS2 by substitutional doping. Nature Communications (2018).
2. Beating the exclusion rule against the coexistence of robust luminescence and ferromagnetism in chalcogenide monolayers. Nature Communications (2019).
3. Spatially selective p-type doping for constructing lateral WS2 p-n homojunction via low-energy nitrogen ion implantation. Light: Science & Applications (2024).
4. Intralayer/Interlayer Codoping Stabilizes Polarity Modulation in 2D Semiconductors for Scalable Electronics. Advanced Science (2024).
5. Molten‐Salt‐Assisted Chemical Vapor Deposition Process for Substitutional Doping of Monolayer MoS2 and Effectively Altering the Electronic Structure and Phononic Properties. Advanced Science (2020).