Electronic properties of bare and functionalized two-dimensional (2D) tellurene structures
Electronic properties of bare and functionalized two-dimensional (2D) tellurene structures
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DOI：
10.1039/d0cp00357c
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发表时间：
2020-03-28
影响因子：
3.3
通讯作者：
Ataca，Can
中科院分区：
文献类型：
--
作者：
Wines，Daniel;Kropp，Jaron A.;Ataca，Can
最近，二维碲（Te）结构已被实验合成。这些结构具有高的载流子迁移率和稳定性，使它们成为电子学、光电子学和能源器件中应用的理想候选者。我们进行了密度泛函理论（DFT）和分子动力学（MD）模拟，以研究二维α-和β-Te片层以及氢、氧和氟官能化对应物的稳定性和电子结构，包括自旋轨道耦合效应。计算结果表明，裸露的α和β-Te片是稳定的，带隙分别为0.44 eV和1.02 eV。当官能化时，α和β单层表现出金属性质，除了氢化的β-Te，其表现出半导体性质，带隙为1.37 eV。我们看到H、O和F使α-Te的结构不稳定。我们还发现F和H使β-Te层分离成功能化的原子链，O使β-Te转变成Te_3O_2类结构。我们还研究了单一的原子和分子的Te表面上的结合，吸附原子覆盖的影响，和功能化的Te的影响，在GaSe衬底。我们的研究结果表明，碲烯单分子膜和功能化的对应物不仅适用于未来的光电器件，但可以用作纳米结中的金属接触。
Recently, 2D tellurene (Te) structures have been experimentally synthesized. These structures possess high carrier mobility and stability which make them ideal candidates for applications in electronics, optoelectronics and energy devices. We performed density functional theory (DFT) and molecular dynamics (MD) simulations to investigate the stability and electronic structure of 2D α- and β-Te sheets, and hydrogen, oxygen, and fluorine functionalized counterparts, including spin–orbit coupling effects. Our calculations show that bare α and β-Te sheets are stable with band gaps of 0.44 eV and 1.02 eV respectively. When functionalized, α and β monolayers exhibit metallic properties, except for hydrogenated β-Te, which exhibits semiconducting properties with a band gap of 1.37 eV. We see that H, O and F destabilize the structure of α-Te. We also find that F and H cause β-Te layers to separate into functionalized atomic chains and O causes β-Te to transform into a Te3O2-like structure. We also studied single atom and molecule binding on the Te surface, the effects of adatom coverage, and the effects of functionalized Te on a GaSe substrate. Our results indicate that tellurene monolayers and functionalized counterparts are not only suitable for future optoelectronic devices, but can be used as metallic contacts in nanoscale junctions.