Key Laboratory of Advanced Display Materials and Devices, Ministry of Industry and Information Technology, College of Material Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Nanoscale. 2018 May 10;10(18):8397-8403. doi: 10.1039/c8nr01028e.
An effectively large bandgap and a high carrier mobility of two dimensional (2D) crystals are crucial in emerging materials for nanoelectronics. A previously unexplored two-dimensional material, monolayer TeO2, is proposed to have high stability, a wide direct gap and high carrier mobility, based on first-principles calculations. Our results show that 2D TeO2 is both thermally and dynamically stable. In addition, it is easily exfoliated from its bulk counterpart, a natural layered mineral tellurite. Importantly, 2D TeO2 always exhibits a direct bandgap when thinning from bulk (3.32 eV) to monolayer (3.70 eV), an energy range not covered by previously reported 2D materials. Furthermore, monolayer TeO2 is exceptional in high transport anisotropy, possessing not only high electron mobility (of the order of 1000 cm2 V-1 s-1) but also exceptionally high hole mobility (up to 9100 cm2 V-1 s-1). All these findings make 2D TeO2 a promising candidate for both power electronics and short-wavelength optoelectronic applications.
二维（2D）晶体具有有效的大带隙和高载流子迁移率，这对于新兴的纳米电子材料至关重要。基于第一性原理计算，提出了一种以前未被探索的二维材料——单层 TeO2，其具有高稳定性、宽直接带隙和高载流子迁移率。我们的结果表明，2D TeO2 在热力学和动力学上都是稳定的。此外，它很容易从其体相对应物——天然层状矿物碲酸盐中剥离出来。重要的是，当从体相（3.32eV）减薄到单层（3.70eV）时，2D TeO2 始终表现出直接带隙，这一能量范围没有被之前报道的二维材料所涵盖。此外，单层 TeO2 在高传输各向异性方面表现出色，不仅具有高电子迁移率（约为 1000cm2 V-1 s-1），而且还具有异常高的空穴迁移率（高达 9100cm2 V-1 s-1）。所有这些发现都使得 2D TeO2 成为功率电子学和短波长光电子学应用的有前途的候选材料。
