Prolonged photo-carriers generated in a massive-and-anisotropic Dirac material
arXiv:1805.12327
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.
arXiv comment13 pages, 5 figures
References in corpus (17)
- Rediscovering Black Phosphorus: A Unique Anisotropic 2D Material for Optoelectronics and Electronics
- Observation of tunable bandgap and anisotropic Dirac semimetal state in black phosphorus
- Direct view on the ultrafast carrier dynamics in graphene
- Ultrafast Electronic Band Gap Control in an Excitonic Insulator
- Excitonic Bose-Einstein condensation in Ta2NiSe5 above room temperature
- Dynamical Evolution of Anisotropic Response in Black Phosphorus under Ultrafast Photoexcitation
- On the possibility of an excitonic insulator at the semiconductor-semimetal transition
- Ultrafast Dynamics of Massive Dirac Fermions in Bilayer Graphene
- Tracking primary thermalization events in graphene with photoemission at extreme timescales
- Electronic Structures of Black Phosphorus Studied by Angle-resolved Photoemission Spectroscopy
- Electron-hole pair condensation at the semimetal-semiconductor transition: a BCS-BEC crossover scenario
- Revealing the ultrafast light-to-matter energy conversion before heat diffusion in a layered Dirac semimetal
- Photo-induced superconductivity in semiconductors
- Observation of Preformed Electron-Hole Cooper Pairs
- Excitonic instability in optically-pumped three-dimensional Dirac materials
- Nonequilibrium phonon dynamics beyond the quasiequilibrium approach
- Onset of exciton-exciton annihilation in single layer black phosphorus