Substitutional transition metal doping in MoS₂: a first-principles study

Abstract

Single-layer MoS 2 is a direct-gap semiconductor whose band edges character is dominated by the d-orbitals of the Mo atoms. It follows that substitutional doping of the Mo atoms has a significant impact on the material's electronic properties, namely the size of the band gap and the position of the Fermi level. Here, density functional theory is used along with the G 0 W 0 method to examine the effects of substituting Mo with four different transition metal dopants: Nb, Tc, Ta, and Re. Nb and Ta possess one less valence electron than Mo does and are therefore p-type dopants, while Re and Tc are n-type dopants, having one more valence electron than Mo has. Four types of substitutional structures are considered for each dopant species: isolated atoms, lines, three-atom clusters centered on a S atom (c3s), and three-atom clusters centered on a hole (c3h). The c3h structure is found to be the most stable configuration for all dopant species. However, electronic structure calculations reveal that isolated dopants are preferable for efficient n-or p-type performance. Lastly, it is shown that photoluminescence measurements can provide valuable insight into the atomic structure of the doped material. Understanding these properties of substitutionally-doped MoS 2 can allow for its successful implementation into cutting-edge solid state devices.

Electronic properties of germanene on pristine and defective MoS2 : A first-principles study

“…4, we show the formation energies for all the defects considered in our paper. We can see that substitutional defects have a low formation energy which is in agreement with previous calculations [31].…”

“…where μ Mo is the chemical potential of Mo, obtained from the bcc molybdenum structure, and μ S is the chemical potential of S, which is calculated using μ Mo and the total energy of a MoS 2 monolayer (E tot [MoS 2 ]) [31]. The chemical potentials of the substitutional atoms such as Re, Zr, and Nb are determined by the total energy of their monolayer dichalcogenide form:…”

Tuning the optical properties of monolayer WS2 for near-infrared-II photothermal therapy: a first-principles study

“…For X site substitution, one of the eight sulfur atoms were replaced, giving a 12.5% concentration. 50,51 This can be seen in Fig. 2.…”

“…If the atomic radius of the dopant is similar to that of the host, a minor strain will be put on the crystal structure, maintaining a clean and stable surface. 51 Substitutional doping of the sulfur atom has also been tested for WS 2 , creating bond changes and altering the bandgap. 61 With a 2 Â 2 supercell, substitutional doping was carried out.…”

A High‐Speed Photodetector Fabricated with Tungsten‐Doped MoS2 by Ion Implantation

“…[6,8,13,[17][18][19][23][24][25] But due to its limited electrical and optical properties of pure MoS 2 , a universal metal doping method to control its performance is urgently needed. [26][27][28] In fact, many methods, including surface engineering, [29] plasma treatment, [30] molecular adsorption with charge transfer, [27] chemical doping, [31][32][33] and metal work-function engineering [34,35] are dedicated to realizing metal doping. [27,28,[36][37][38] However, these methods bring about some inevitable disadvantages, such as uncontrollability, degraded performance, complicated process, harsh doping conditions, and difficulty in large-area preparation.Ion implantation technology has been generally used in industrial semiconductor applications.…”