2018/05/31 by Munisa Nurmamat, Nurmamat, Munisa, Y. Ishida +19 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Perovskite Materials and Applications #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.1805.12327
openalex publication_date 2018/05/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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.