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The optical conductivity of few-layer black phosphorus by infrared spectroscopy.

ABSTRACT: The strength of light-matter interaction is of central importance in photonics and optoelectronics. For many widely studied two-dimensional semiconductors, such as MoS2, the optical absorption due to exciton resonances increases with thickness. However, here we will show, few-layer black phosphorus exhibits an opposite trend. We determine the optical conductivity of few-layer black phosphorus with thickness down to bilayer by infrared spectroscopy. On the contrary to our expectations, the frequency-integrated exciton absorption is found to be enhanced in thinner samples. Moreover, the continuum absorption near the band edge is almost a constant, independent of the thickness. We will show such scenario is related to the quanta of the universal optical conductivity of graphene (?0?=?e2/4?), with a prefactor originating from the band anisotropy.

SUBMITTER: Zhang G

PROVIDER: S-EPMC7160205 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature

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The optical conductivity of few-layer black phosphorus by infrared spectroscopy.

Zhang Guowei G Huang Shenyang S Wang Fanjie F Xing Qiaoxia Q Song Chaoyu C Wang Chong C Lei Yuchen Y Huang Mingyuan M Yan Hugen H

Nature communications 20200415 1

The strength of light-matter interaction is of central importance in photonics and optoelectronics. For many widely studied two-dimensional semiconductors, such as MoS<sub>2</sub>, the optical absorption due to exciton resonances increases with thickness. However, here we will show, few-layer black phosphorus exhibits an opposite trend. We determine the optical conductivity of few-layer black phosphorus with thickness down to bilayer by infrared spectroscopy. On the contrary to our expectations, ...[more]

PMID: 32296052

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