Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588 (USA).
Angew Chem Int Ed Engl. 2015 Jun 22;54(26):7572-6. doi: 10.1002/anie.201502107. Epub 2015 May 12.
A new two-dimensional (2D) layered material, namely, titanium trisulfide (TiS3 ) monolayer, is predicted to possess novel electronic properties. Ab initio calculations show that the perfect TiS3 monolayer is a direct-gap semiconductor with a bandgap of 1.02 eV, close to that of bulk silicon, and with high carrier mobility. More remarkably, the in-plane electron mobility of the 2D TiS3 is highly anisotropic, amounting to about 10 000 cm(2) V(-1) s(-1) in the b direction, which is higher than that of the MoS2 monolayer, whereas the hole mobility is about two orders of magnitude lower. Furthermore, TiS3 possesses lower cleavage energy than graphite, suggesting easy exfoliation for TiS3 . Both dynamical and thermal stability of the TiS3 monolayer is examined by phonon-spectrum calculation and Born-Oppenheimer molecular dynamics simulation. The desired electronic properties render the TiS3 monolayer a promising 2D atomic-layer material for applications in future nanoelectronics.
一种新的二维（2D）层状材料，即三硫化钛（TiS3）单层，被预测具有新颖的电子特性。从头算计算表明，完美的 TiS3 单层是直接带隙半导体，带隙为 1.02eV，接近体硅，并且具有高载流子迁移率。更显著的是，二维 TiS3 的面内电子迁移率具有高度各向异性，在 b 方向上约为 10000cm2V-1s-1，高于 MoS2 单层，而空穴迁移率则低两个数量级。此外，TiS3 的剥离能低于石墨，表明 TiS3 易于剥离。通过声子谱计算和 Born-Oppenheimer 分子动力学模拟来检验 TiS3 单层的动力学和热稳定性。所期望的电子特性使得 TiS3 单层成为未来纳米电子学应用中有前途的二维原子层材料。
