Controllable p‐Type Doping of 2D WSe₂ via Vanadium Substitution

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 WSe 2 at front-end-of-line and backend-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 WSe 2 , which results in p-type doping via the introduction of discrete defect levels that lie close to the valence band maxima. The p-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.

Femtomolar‐Level Molecular Sensing of Monolayer Tungsten Diselenide Induced by Heteroatom Doping with Long‐Term Stability

“…The PL peaks in high Re‐WSe 2 and Nb, Re‐WSe 2 are greatly quenched, possibly due to the increased density of trions induced by the dopants. [ 28 ]…”

“…The PL peaks in high Re-WSe 2 and Nb, Re-WSe 2 are greatly quenched, possibly due to the increased density of trions induced by the dopants. [28] The chemical valence and electronic structure of pristine and doped WSe 2 were examined by X-ray photoelectron spectroscopy (XPS). The binding energy peaks of W 4f core levels in pristine WSe 2 located at 34.4 and 32.3 eV can be assigned to W 4f 5/2 and W 4f 7/2 in Figure 2c, [29] respectively.…”

Heterogeneous Integration of Atomically Thin Semiconductors for Non‐von Neumann CMOS

“…[30,31] More recently, we have demonstrated controllable p-type doping of MOCVD WSe 2 via Vanadium substitution. [32] Although these research efforts highlight the potential of TMDs for CMOS integrated circuit (IC) technology, certain processing, fabrication, and design constraints must be mitigated. This includes large area uniform growth, clean and damage-free transfer, and heterogeneous integration and precise positioning of p-type and n-type material on the same substrate for efficient circuit design.…”

Defect‐Engineered Magnetic Field Dependent Optoelectronics of Vanadium Doped Tungsten Diselenide Monolayers

“…Monolayer semiconducting transition metal dichalcogenides (TMDCs) of group IV transition metals, such as MoS 2 , WS 2 , and WSe 2 , exhibit direct band gaps in the visible range and a weak dielectric screening, with the latter significantly Calculations for TMDC monolayers, such as MoS 2 and WS 2 , suggest that doping with manganese, nickel, niobium, tantalum or vanadium can induce ferromagnetic order with Curie temperatures up to 170 K. [8,15,16] Among different host materials, monolayer WSe 2 is deemed especially suitable due to its good ambipolar gate tunability and larger spin-orbit splitting compared to the Mo-based TMDCs, which can be beneficial for stabilizing the magnetic order. [13,[17][18][19][20][21] Furthermore, (doped) WSe 2 bulk crystals can be grown at low defect densities, enabling proof-of-concept devices, but also high quality wafer-scale monolayers can be grown by metal organic chemical vapor deposition (CVD), ensuring scalability and applicability. [2,13,22] In vanadium-doped WSe 2 , theoretical and experimental works have provided first evidence for a room temperature, long-range, (ferro)magnetic order.…”

“…[9,10] A natural choice for (magnetic) dopants are other transition metals, since they incorporate easily into the metal sublattice. [11][12][13][14] The ability to dope transition metal dichalcogenides such as tungsten diselenide (WSe 2 ) with magnetic transition metal atoms in a controlled manner has motivated intense research with the aim of generating dilute magnetic semiconductors. In this work, semiconducting WSe 2 monolayers, substitutionally doped with vanadium atoms, are investigated using low-temperature luminescence and optoelectronic spectroscopy.…”