Liu Xinyi, Ren Ji-Chang, Zhang Shufang, Fuentes-Cabrera Miguel, Li Shuang, Liu Wei
Nano and Heterogeneous Materials Center, School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China.
School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China.
J Phys Chem Lett. 2018 Jul 19;9(14):3897-3903. doi: 10.1021/acs.jpclett.8b01589. Epub 2018 Jul 2.
Conductivity of two-dimenstional (2D) materials, which largely determines the efficiency and reliability of nanodevices, is proportional to the product of carrier concentration and mobility. Conventional doping, such as ionic substitution or introduction of vacancies, increases carrier concentration and decreases carrier mobility due to the scattering or trapping of carriers. We propose a remote-doping strategy that enables the simultaneous enhancement of both parameters. Density functional theory calculations in 2D InSe reveal that adsorbing the molecule tetrathiafulvalene (TTF) and applying a 4% external tensile strain leads to an increase in the carrier concentration of the TTF-InSe system that is 13 orders of magnitude higher than that of the pristine counterpart, whereas the carrier mobility is enhanced by 35% compared with the InSe monolayer. As a consequence of the synergetic role of molecule doping and strain engineering, ultrahigh conductivity of 1.85 × 10 S/m is achieved in the TTF-InSe system at room temperature.
二维（2D）材料的电导率在很大程度上决定了纳米器件的效率和可靠性，它与载流子浓度和迁移率的乘积成正比。传统的掺杂方法，如离子取代或引入空位，会增加载流子浓度，但由于载流子的散射或捕获而降低载流子迁移率。我们提出了一种远程掺杂策略，可同时提高这两个参数。二维InSe中的密度泛函理论计算表明，吸附分子四硫富瓦烯（TTF）并施加4%的外部拉伸应变会导致TTF-InSe系统的载流子浓度增加，比原始对应物高13个数量级，而与InSe单层相比，载流子迁移率提高了35%。由于分子掺杂和应变工程的协同作用，TTF-InSe系统在室温下实现了1.85×10 S/m的超高电导率。
