Sizable bandgaps of graphene in 3d transition metal intercalated defective graphene/WSe₂ heterostructures

Abstract

Controlling the electronic and magnetic properties of G/TMD (graphene on transition metal dichalcogenide) heterostructures is essential to develop electronic devices. Despite extensive studies in perfecting G/TMDs, most products have various defects due to the limitations of the fabrication techniques, and research investigating the performances of defective G/TMDs is scarce. Here, we conduct a comprehensive study of the effects of 3d transition metal (TM ¼ Sc-Ni) atom-intercalated G/ WSe 2 heterostructures, as well as their defective configurations having single vacancies on graphene or WSe 2 sublayers. Interestingly, Ni-intercalated G/WSe 2 exhibits a small band gap of 0.06 eV, a typical characteristic of nonmagnetic semiconductors. With the presence of one single vacancy in graphene, nonmagnetic (or ferromagnetic) semiconductors with sizable band gaps, 0.10-0.51 eV, can be achieved by intercalating Ti, Cr, Fe and Ni atoms into the heterostructures. Moreover, V and Mn doped nondefective and Sc, V, Co doped defective G/WSe 2 can lead to sizable half metallic band gaps of 0.1-0.58 eV. Further analysis indicates that the significant electron transfer from TM atoms to graphene accounts for the opening of a large band gap. Our results provide theoretical guidance to future applications of G/TMD based heterostructures in (spin) electronic devices.

First-Principles Study of the Optical Properties of TMDC/Graphene Heterostructures

“…The SBH are Φ Bn = 0.29 eV and Φ Bp = 1.23 eV for MoS 2 /Gr, Φ Bn = 0.75 eV and Φ Bp = 0.65 eV for MoSe 2 /Gr, Φ Bn = 0.39 eV and Φ Bp = 1.13 eV for WS 2 /Gr, and Φ Bn = 1.00 eV and Φ Bp = 0.61 eV for WSe 2 /Gr, respectively. Therefore, MoS 2 /Gr, MoSe 2 /Gr, WS 2 /Gr and WSe 2 /Gr are the n-type, p-type, n-type and p-type Schottky contacts, respectively [64,66,67].…”

“…On the other hand, the MX 2 /Gr of the type-I van der Waals heterostructures have attracted much attention for their electronic properties. Research on MoS 2 /Gr [60][61][62], MoSe 2 /Gr [63][64][65], WS 2 /Gr [66] and WSe 2 /Gr [67,68] has revealed that MX 2 /Gr is favorable for electronics applications and field-effect transistors. However, there are relatively few studies on its optical properties [69][70][71]; therefore, comprehensive research on the optical properties of MX 2 /Gr is desired.…”

First Principle Study for Optical Properties of TMDCs/Graphene Heterostructures

“…Φ Bp = 0.65eV for MoSe 2 /Gr, Φ Bn = 0.39eV and Φ Bp = 1.13eV for WS 2 /Gr, and Φ Bn = 1.00eV and Φ Bp = 0.61eV for WSe 2 /Gr, respectively. Therefore, MoS 2 /Gr, MoSe 2 /Gr, WS 2 /Gr and WSe 2 /Gr are the n-type, p-type, n-type and p-type Schottky contacts, respectively [47,49,51].…”

“…The MX 2 /Gr are the type-I van der Waals heterostructures. The electronic properties of MoS 2 /Gr [33,[42][43][44][45], MoSe 2 /Gr [28,[46][47][48], WS 2 /Gr [29,49] and WSe 2 /Gr [50][51][52] have been revealed that MX 2 /Gr van der Waals heterostructures are favourable for optoelectronic applications and field-effect transistors. In this paper, we theoretically investigate the optical properties of MX 2 /Gr (M=Mo,W; X=S,Se) heterostructures.…”

Effect of 3d Transition Metal Atom Intercalation Concentration on the Electronic and Magnetic Properties of Graphene/MoS2 Heterostructure: A First-Principles Study

“…Furthermore, Li intercalation has been shown to tune conductivity in several layers of MoS 2 [ 30 ] and graphene/MoX 2 (X = S, Se) [ 31 ] heterostructures by more than two to three orders of magnitude. Furthermore, a 3 d transition metal (TM) atom-intercalated bilayer graphene [ 32 , 33 ], bilayer borophene [ 34 ], G/MoS 2 [ 35 ], G/WS 2 [ 35 ], G/WSe 2 [ 36 ], and defective G/WSe 2 [ 36 ] were found to introduce new electronic and magnetic properties. It is noted that the properties of intercalation compounds should be closely related to the concentration of the intercalated atoms, which is easy to control in experiments [ 20 ].…”