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.
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http://dx.doi.org/10.1038/s41598-018-27133-6 | DOI Listing |
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January 2025
Key Laboratory of Eco-chemical Engineering, International S&T Cooperation Foundation of Eco-chemical Engineering and Green Manufacture, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, P. R. China.
Crafting anisotropically epitaxial p-n heterostructures with Z-scheme charge transmission is a promising avenue toward excellent photocatalytic efficiency, yet the large lattice mismatch and diverse crystal growth habits between components have often arisen as a big challenge to this goal. Here, anisotropically epitaxial p-n heterostructures with 19.8% lattice mismatch are obtained via a dynamics-mediated seeded growth tactic under reaction temperature as low as 60 °C.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2022
Department of Metallurgical Engineering, College of Materials and Metallurgy, Guizhou University, Huaxi, Guiyang, Guizhou, 550025, China.
Tuning morphology and doping additional rare earth (RE) cations are potential techniques to promote the photocatalytic performance of ceria (CeO), evaluating the collaborative effects of morphology and RE dopants is significant for producing high active ceria-based catalysts. So in this work, cubic, polyhedral and rod-like nanoceria doped with 10 mol % La (lanthanum), Y (yttrium), or Sm (samarium) were synthesized by a facile template-free hydrothermal method. Phases, morphologies, oxygen vacancies (OVs) concentration, energy band structure, photo-carriers separation/recombination, and photodegradation ratio toward methylene blue (MB) dye of as prepared ceria were studied.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2022
College of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science & Technology, Xi'an, Shaanxi 710021, China. Electronic address:
Solar driven water-to-hydrogen conversion is a promising technology for the typical sustainable production mode, so increasing efforts are being devoted to exploit high-performance photocatalytic materials. Cadmium sulfide (CdS) is widely used to prepare highly active photocatalysts owing to its merits of broadband-light harvesting and feasible band structure. However, the slow photo-carriers' migration in CdS body structure generally results in high-frequency carriers recombination, which leads to unsatisfied photoactivity.
View Article and Find Full Text PDFNanomicro Lett
December 2021
School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, People's Republic of China.
The recombination loss of photo-carriers in photocatalytic systems fatally determines the energy conversion efficiency of photocatalysts. In this work, an electrostatic field was used to inhibit the recombination of photo-carriers in photocatalysts by separating photo-holes and photo-electrons in space. As a model structure, (010) facet-exposed BiVO nanowires were grown on PDMS-insulated piezo-substrate of piezoelectric transducer (PZT).
View Article and Find Full Text PDFSci Rep
August 2021
Laboratory of Physics of Complex Matter, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
Interest in fast and easy detection of high-energy radiation (x-, γ-rays and neutrons) is closely related to numerous practical applications ranging from biomedicine and industry to homeland security issues. In this regard, crystals of hybrid halide perovskite have proven to be excellent detectors of x- and γ-rays, offering exceptionally high sensitivities in parallel to the ease of design and handling. Here, we demonstrate that by assembling a methylammonium lead tri-bromide perovskite single crystal (CHNHPbBr SC) with a Gadolinium (Gd) foil, one can very efficiently detect a flux of thermal neutrons.
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