期刊
NANO LETTERS
卷 16, 期 9, 页码 5568-5573出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.nanolett.6b02118
关键词
Exciton; 2D material; doping dynamical effects; Bethe-Salpeter equation
类别
资金
- National Science Foundation (NSF) CAREER Grant [DMR-1455346]
- NSF [EFRI-2DARE-1542815]
- Laboratory Directed Research and Development program at Sandia National Laboratories
- United States Department of Energy's National Nuclear Security Administration [DE-AC04-94AL85000]
- Directorate For Engineering
- Emerging Frontiers & Multidisciplinary Activities [1542815] Funding Source: National Science Foundation
It is well-known that excitonic effects can dominate the optical properties of two-dimensional materials. These effects, however, can be substantially modified by doping free carriers. We investigate these doping effects by solving the first-principles BetheSalpeter equation. Dynamical screening effects, included via the sum-rule preserving generalized plasmon-pole model, are found to be important in the doped system. Using monolayer MoS2 as an example, we find that upon moderate doping, the exciton binding energy can be tuned by a few hundred millielectronvolts, while the exciton peak position stays nearly constant due to a cancellation with the quasiparticle band gap renormalization. At higher doping densities, the exciton peak position increases linearly in energy and gradually merges into a Fermi-edge singularity. Our results are crucial for the quantitative interpretation of optical properties of two-dimensional materials and the further development of ab initio theories of studying charged excitations such as trions.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据