论文标题
高$κ$介电基板的2D材料中的异常非氢化激素系列
Anomalous Non-Hydrogenic Exciton Series in 2D Materials on High-$κ$ Dielectric Substrates
论文作者
论文摘要
介电环境的工程是控制二维（2D）材料的电子和光学特性的强大策略，而不会损害其结构完整性。在这里，我们表明，高$κ$ 2D材料的最新发展为电介质工程提供了新的机会。通过使用从第一原理获得的筛选电子孔相互作用求解不同基板上的WSE $ _2 $的2D Mott-Wannier Inviton模型，我们证明了当2D半导体内的介电筛选在2D半导体中占主导地位时，Ickiton Rydberg系列会在定性上发生变化。在此制度中，筛选的距离依赖性逆转，有效筛选随激子半径增加而增加，激子半径与常规2D筛选状态相反。因此，与氢化的rydberg系列相比，较高的激子状态变得越来越多，而不是越来越大。最后，我们得出了整个2D Rydberg系列的激子结合能的一般分析表达
Engineering of the dielectric environment represents a powerful strategy to control the electronic and optical properties of two-dimensional (2D) materials without compromising their structural integrity. Here we show that the recent development of high-$κ$ 2D materials present new opportunities for dielectric engineering. By solving a 2D Mott-Wannier exciton model for WSe$_2$ on different substrates using a screened electron-hole interaction obtained from first principles, we demonstrate that the exciton Rydberg series changes qualitatively when the dielectric screening within the 2D semiconductor becomes dominated by the substrate. In this regime, the distance dependence of the screening is reversed and the effective screening increases with exciton radius, which is opposite to the conventional 2D screening regime. Consequently, higher excitonic states become underbound rather than overbound as compared to the Hydrogenic Rydberg series. Finally, we derive a general analytical expression for the exciton binding energy of the entire 2D Rydberg series
