Durán Retamal José Ramón, Periyanagounder Dharmaraj, Ke Jr-Jian, Tsai Meng-Lin, He Jr-Hau
Computer, Electrical and Mathematical Sciences and Engineering , King Abdullah University of Science and Technology , Thuwal , 23955-6900 , Kingdom of Saudi Arabia . Email:
Chem Sci. 2018 Sep 24;9(40):7727-7745. doi: 10.1039/c8sc02609b. eCollection 2018 Oct 28.
Ever since two dimensional-transition (2D) metal dichalcogenides (TMDs) were discovered, their fascinating electronic properties have attracted a great deal of attention for harnessing them as critical components in novel electronic devices. 2D-TMDs endowed with an atomically thin structure, dangling bond-free nature, electrostatic integrity, and tunable wide band gaps enable low power consumption, low leakage, ambipolar transport, high mobility, superconductivity, robustness against short channel effects and tunneling in highly scaled devices. However, the progress of 2D-TMDs has been hampered by severe charge transport issues arising from undesired phenomena occurring at the surfaces and interfaces. Therefore, this review provides three distinct engineering strategies embodied with distinct innovative approaches to optimize both carrier injection and transport. First, contact engineering involves 2D-metal contacts and tunneling interlayers to overcome metal-induced interface states and the Fermi level pinning effect caused by low vacancy energy formation. Second, dielectric engineering covers high- dielectrics, ionic liquids or 2D-insulators to screen scattering centers caused by carrier traps, imperfections and rough substrates, to finely tune the Fermi level across the band gap, and to provide dangling bond-free media. Third, material engineering focuses on charge transfer substitutional, chemical and plasma doping to precisely modulate the carrier concentration and to passivate defects while preserving material integrity. Finally, we provide an outlook of the conceptual and technical achievements in 2D-TMDs to give a prospective view of the future development of highly scaled nanoelectronic devices.
自从二维过渡（2D）金属二硫属化物（TMDs）被发现以来，其迷人的电子特性吸引了大量关注，有望将它们用作新型电子器件中的关键组件。具有原子级薄结构、无悬空键性质、静电完整性和可调宽带隙的二维TMDs能够实现低功耗、低泄漏、双极性传输、高迁移率、超导性、对短沟道效应的鲁棒性以及在高度缩放器件中的隧穿。然而，二维TMDs的发展受到表面和界面处出现的不良现象所导致的严重电荷传输问题的阻碍。因此，本综述提供了三种不同的工程策略，这些策略体现了不同的创新方法，以优化载流子注入和传输。首先，接触工程涉及二维金属接触和隧穿中间层，以克服金属诱导的界面态以及由低空位能量形成引起的费米能级钉扎效应。其次，介电工程涵盖高介电常数材料、离子液体或二维绝缘体以屏蔽由载流子陷阱缺陷和粗糙衬底引起的散射中心，精细调节带隙上的费米能级，并提供无悬空键的介质。第三，材料工程专注于电荷转移——替代掺杂、化学掺杂和等离子体掺杂，以精确调制载流子浓度并钝化缺陷，同时保持材料完整性。最后，我们展望了二维TMDs在概念和技术方面的成就，以期对高度缩放的纳米电子器件的未来发展有一个前瞻性的认识。
