Optical and electrical properties of MoS₂ and Fe-doped MoS₂

Abstract

We prepared undoped and Fe-doped MoS2 layered crystals using a chemical vapor transport method to compare their optical and electrical properties. Optical behaviors of carrier transitions were observed successfully in both undoped and Fe-doped MoS2 samples using reflectance and piezoreflectance. Frequency-dependent photoconductivity (PC) measurements reveal an additional deep Fe doping level for the Fe-doped MoS2 sample. In addition, a longer carrier lifetime was calculated for the Fe-doped MoS2 sample than for the undoped MoS2 sample through PC analysis. Hall measurements were also performed for both samples and indicated that the Fe-doped MoS2 sample exhibited a higher carrier concentration and a lower mobility owing to the effect of Fe dopants. Furthermore, both samples were confirmed to have n-type carriers.

Thickness determination of MoS2, MoSe2, WS2 and WSe2 on transparent stamps used for deterministic transfer of 2D materials

“…The Fe-doped, Ni-doped, Nb-doped and Co-doped MoS2 crystals were grown following the protocols described in Refs. [37][38][39][40]. A 0.5% of dopant material has been added during the synthesis of these doped MoS2 samples which leads to a final doping level in the 0.3-0.4% range.…”

“…[35,36] We further test the analysis of the blue channel transmission images by studying MoS2 samples synthesized with intentional substitutional metal atoms at the Mo sites to enquiry about the robustness of this technique against a moderate variation of the chemical composition that lead to a big change in the electronic properties. [37,38] We follow the synthesis method described in references [37][38][39][40] for the growth of Fe-doped, Ni-doped, Nb-doped and Co-doped MoS2 crystals. In all cases a 0.5% of dopant material has been added in the ampoule for the synthesis of these doped MoS2 samples which lead to a final doping level in the 0.3-0.4% range.…”

Various Structures of 2D Transition‐Metal Dichalcogenides and Their Applications

“…Theoretically, the mobility is related to scattering and electron effective masswhere μ is the mobility, q represents the electron charge, τ is mean free time of an electron, and m * represents the electron effective mass. For 2D doped TMDs, carrier scattering is enhanced and the mean free time of electrons is reduced, which decreases the mobility . Thus, designing 2D doped TMDs with small electron effective mass is an effective strategy to increase the mobility .…”

Recent Advances in Doping of Molybdenum Disulfide: Industrial Applications and Future Prospects

“…Substitutional doping during MoS 2 growth can be achieved by vapor deposition of Se and/or MoSe 2 for Se dopant, by the controlled thermal/optical annealing activation process after depositing phosphorus silicate glass (PSG) for phosphor doping and transferring MoS 2, by chemical vapor transport (CVT) approach using Br 2 , I 2, etc. as transportation agents for dopants such as Re, or Co, Fe, or Nb, or Au, by chemical vapor deposition (CVD) using chlorides such as ReCl 2 and NbCl 5 for the doping of Re and Nb, by diffusion of a ML (Mo/Nb/Mo or transition metal (Fe, Co, Ni, Cu)/Mo) for Nb and transition metals (TMs) . during sulfurization, or by metal organic power (Mn 2 (CO) 10 ) vaporization for Mn dopant .…”

“…The CVT method is a very simple and convenient one step process for combining MoS 2 synthesis and substitutional doping for dopants such as Re (n‐type), Co, Fe (n‐type), Nb (p‐type), and Au (p‐type) . The schematic diagram for CVT using I 2 as a transport agent used for the Nb‐doped MoS 2 growth is shown in Figure .…”