Bahmani Mohammad, Ghorbani-Asl Mahdi, Frauenheim Thomas
Bremen Center for Computational Materials Science (BCCMS), Department of Physics, Bremen University 28359 Bremen Germany mbahmani@uni/bremen.de +49 421 21862338.
Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf 01328 Dresden Germany
RSC Adv. 2021 Nov 25;11(60):37995-38002. doi: 10.1039/d1ra06010d. eCollection 2021 Nov 23.
The coexistence of semiconducting (2H) and metallic (1T) phases of MoS monolayers has further pushed their strong potential for applications in the next generation of electronic devices based on two-dimensional lateral heterojunctions. Structural defects have considerable effects on the properties of these 2D devices. In particular, the interfaces of two phases are often imperfect and may contain numerous vacancies created by phase engineering techniques, under an electron beam. Here, the transport behaviors of the heterojunctions with the existence of point defects are explored by means of first-principles calculations and non-equilibrium Green's function approach. While vacancies in semiconducting MoS act as scattering centers, their presence at the interface improves the flow of the charge carriers. In the case of V, the current has been increased by two orders of magnitude in comparison to the perfect device. The enhancement of transmission was explained by changes in the electronic densities at the T-H interface, which open new transport channels for electron conduction.
二硫化钼单层的半导体(2H)相和金属(1T)相的共存,进一步推动了它们在基于二维横向异质结的下一代电子器件中的强大应用潜力。结构缺陷对这些二维器件的性能有相当大的影响。特别是,两相的界面往往不完美,可能包含通过相工程技术在电子束下产生的大量空位。在此,通过第一性原理计算和非平衡格林函数方法,探索了存在点缺陷时异质结的输运行为。虽然半导体二硫化钼中的空位充当散射中心,但它们在界面处的存在改善了电荷载流子的流动。对于V的情况,与完美器件相比,电流增加了两个数量级。传输增强是由T-H界面处电子密度的变化来解释的,这为电子传导开辟了新的传输通道。