期刊
PHYSICAL REVIEW MATERIALS
卷 2, 期 1, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevMaterials.2.011001
关键词
-
资金
- ERC [306719]
- ITN Spin-NANO Marie Sklodowska-Curie Grant [676108]
- ANR MoS2ValleyControl
- ANR VallEx
- Elemental Strategy Initiative
- JSPS KAKENHI [JP15K21722]
- LIA ILNACS
- RFBR [17-02-00383, 17-52-16020]
- RF President Grant [MD-1555.2017.2]
- Government of the Russian Federation [14.W03.31.0011]
- NSF [DMR-1552220]
The optical properties of MoS2 monolayers are dominated by excitons, but for spectrally broad optical transitions in monolayers exfoliated directly onto SiO2 substrates detailed information on excited exciton states is inaccessible. Encapsulation in hexagonal boron nitride (hBN) allows approaching the homogenous exciton linewidth, but interferences in the van der Waals heterostructures make direct comparison between transitions in optical spectra with different oscillator strength more challenging. Here we reveal in reflectivity and in photoluminescence excitation spectroscopy the presence of excited states of the A exciton in MoS2 monolayers encapsulated in hBN layers of calibrated thickness, allowing us to extrapolate an exciton binding energy of approximate to 220 meV. We theoretically reproduce the energy separations and oscillator strengths measured in reflectivity by combining the exciton resonances calculated for a screened two-dimensional Coulomb potential with transfer matrix calculations of the reflectivity for the van der Waals structure. Our analysis shows a very different evolution of the exciton oscillator strength with principal quantum number for the screened Coulomb potential as compared to the ideal two-dimensional hydrogen model.
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