Two-Dimensional Metal/Semiconductor Contact in a Janus MoSH/MoSi₂N₄ van der Waals Heterostructure

Abstract

Following the successful synthesis of single-layer metallic Janus MoSH and semiconducting MoSi 2 N 4 , we investigate the electronic and interfacial features of metal/semiconductor MoSH/MoSi 2 N 4 van der Waals (vdW) contact. We find that the metal/semiconductor MoSH/MoSi 2 N 4 contact forms p-type Schottky contact (p-ShC type) with small Schottky barrier (SB), suggesting that Janus MoSH can be considered as an efficient metallic contact to MoSi 2 N 4 semiconductor with high charge injection efficiency. The electronic structure and interfacial features of the MoSH/MoSi 2 N 4 vdW heterostructure are tunable under strain and electric fields, which give rise to the SB change and the conversion from p-ShC to n-ShC type and from ShC to Ohmic contact. These findings could provide a new pathway for the design of optoelectronic applications based on metal/semiconductor MoSH/MoSi 2 N 4 vdW heterostructures.

Tunability of the electronic properties and contact types of the silicane/MoSi2N4heterostructure under an electric field

“…Similarly, the isolated MoSi 2 N 4 monolayer possesses an indirect band gap of 1.77 eV, forming between the VBM at the Γ point and the CBM at the K point. This value is consistent with the previous reports 50–53 but lower than the experimental value. 11 Additionally, using the HSE06 method, the band gap of the MoSi 2 N 4 monolayer is calculated to be about 2.4 eV, 50–52 which is still greater than the experimental value of 1.94 eV.…”

“…This value is consistent with the previous reports 50–53 but lower than the experimental value. 11 Additionally, using the HSE06 method, the band gap of the MoSi 2 N 4 monolayer is calculated to be about 2.4 eV, 50–52 which is still greater than the experimental value of 1.94 eV. 11 Both the PBE and HSE06 predict the correct trend of materials.…”

Highly Sensitive Band Alignment of the Graphene/MoSi2N4 Heterojunction via an External Electric Field

“…This means that a transition between Schottky contact and Ohmic contact happens again. Note that the larger electric field has been realized in experiments by the pulsed alternating current field technology (0.60 V·Å –1 ) − and in situ surface doping technique (0.72 V·Å –1 ); − we suggest that similar methods can also be performed to generate 0.4 V·Å –1 electric field here. Noteworthily, with a 0.1 V·Å –1 increase of the external electric field, the SBH of the heterojunction apparently varies about 0.2–0.3 eV, greatly larger than that of GR/MoS 2 and GR/AlN heterostructures. , Generally, the external electric field could effectively engineer the barrier heights and types of the GR/MoSi 2 N 4 heterojunction, decreasing the contact resistance and improving the performance of electronic devices. , …”

Rashba-type spin splitting and transport properties of novel Janus XWGeN2 (X = O, S, Se, Te) monolayers

“…26,27 Recently, 2D TMN MoSi 2 N 4 and WSi 2 N 4 have been experimentally fabricated 28 and quickly gained intense interest in the scientific community. [29][30][31] MoSi 2 N 4 (and also WSi 2 N 4 ) has a seven atomic layer structure with a MoN 2 (WN 2 ) monolayer sandwiched between two Si 2 N 2 monolayers. Here, MoN 2 has the same structure as MoS 2 while Si 2 N 2 has the InS-type of structure.…”