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Prolonged photo-carriers generated in a massive-and-anisotropic Dirac material.

ABSTRACT: Transient electron-hole pairs generated in semiconductors can exhibit unconventional excitonic condensation. Anisotropy in the carrier mass is considered as the key to elongate the life time of the pairs, and hence to stabilize the condensation. Here we employ time- and angle-resolved photoemission spectroscopy to explore the dynamics of photo-generated carriers in black phosphorus. The electronic structure above the Fermi level has been successfully observed, and a massive-and-anisotropic Dirac-type dispersions are confirmed; more importantly, we directly observe that the photo-carriers generated across the direct band gap have the life time exceeding 400?ps. Our finding confirms that black phosphorus is a suitable platform for excitonic condensations, and also open an avenue for future applications in broadband mid-infrared BP-based optoelectronic devices.

SUBMITTER: Nurmamat M

PROVIDER: S-EPMC5998121 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

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Prolonged photo-carriers generated in a massive-and-anisotropic Dirac material.

Nurmamat Munisa M Ishida Yukiaki Y Yori Ryohei R Sumida Kazuki K Zhu Siyuan S Nakatake Masashi M Ueda Yoshifumi Y Taniguchi Masaki M Shin Shik S Akahama Yuichi Y Kimura Akio A

Scientific reports 20180613 1

Transient electron-hole pairs generated in semiconductors can exhibit unconventional excitonic condensation. Anisotropy in the carrier mass is considered as the key to elongate the life time of the pairs, and hence to stabilize the condensation. Here we employ time- and angle-resolved photoemission spectroscopy to explore the dynamics of photo-generated carriers in black phosphorus. The electronic structure above the Fermi level has been successfully observed, and a massive-and-anisotropic Dirac ...[more]

PMID: 29899419

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