Black phosphorus (BP) stands out among two-dimensional (2D) semiconductors because of its high mobility and thickness dependent direct band gap. However, the quasiparticle band structure of ultrathin BP has remained inaccessible to experiment thus far. Here we use a recently developed laser-based microfocus angle resolved photoemission (μ-ARPES) system to establish the electronic structure of 2-9 layer BP from experiment. Our measurements unveil ladders of anisotropic, quantized subbands at energies that deviate from the scaling observed in conventional semiconductor quantum wells. We quantify the anisotropy of the effective masses and determine universal tight-binding parameters, which provide an accurate description of the electronic structure for all thicknesses.
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http://dx.doi.org/10.1021/acs.nanolett.3c01226 | DOI Listing |
J Neurosurg Pediatr
January 2025
1Division of Neurosurgery, Department of Surgery, Children's Hospital of Philadelphia.
Objective: The natural history of cephaloceles is not well understood. The goal of this study was to better understand the natural history of fetal cephaloceles from prenatal diagnosis to the postnatal period.
Methods: Between January 2013 and April 2023, all patients evaluated with a cephalocele at the Center for Fetal Diagnosis and Treatment were identified.
Adv Sci (Weinh)
January 2025
School of Resources and Environment, University of Electronic Science and Technology of China, Chengdu, 611731, China.
Heterojunctions, known for their decent separation of photo-generated electrons and holes, are promising for photocatalytic CO reduction. However, a significant obstacle in traditional post-assembled heterojunctions is the high interfacial barrier for charge transfer caused by atomic lattice mismatch at multiphase interfaces. Here, as research prototypes, the study creates a lattice-matched co-atomic interface within CsPbBr-CsPbBr polytypic nanocrystals (113-125 PNs) through the proposed in situ hybrid strategy to elucidate the underlying charge transfer mechanism within this unique interface.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Physics, Rutgers University, Newark 07102, New Jersey, United States.
A striking example of the need to accurately capture states of double-excitation character in molecules is seen in predicting photoinduced dynamics in small polyenes. Due to the coupling of electronic and nuclear motions, the dark 2Ag state, known to have double-excitation character, can be reached after an initial photoexcitation to the bright 1Bu state via crossings of their potential energy surfaces. However, the shapes of the surfaces are so poorly captured by most electronic structure methods, that the crossing is missed or substantially mis-located.
View Article and Find Full Text PDFInorg Chem
January 2025
School of Chemistry and Chemical Engineering, and Institute for Innovative Materials and Energy, Yangzhou University, 180 Si-Wang-Ting Road, Yangzhou 225002, China.
The interaction between electrocatalytic active centers and their support is essential to the electrocatalytic performance, which could regulate the electronic structure of the metal centers but requires precise design. Herein, we report on covalent grafting of graphene quantum dots (GQDs) on stepped TiO as a support to anchoring cobalt phosphide nanoparticles (CoP/GQD/S-TiO) for electrocatalytic hydrogen evolution reaction (HER). The covalent ester bonds between GQDs and TiO endow enlarged anchoring sites to achieve highly dispersed electroactive CoP nanoparticles but, more importantly, provide an efficient electron-transfer pathway from TiO to GQDs which could regulate the electronic structure of CoP.
View Article and Find Full Text PDFCell Rep
January 2025
Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address:
The membrane-proximal external region (MPER) of the HIV-1 envelope is a target for broadly neutralizing antibodies (bnAbs), and vaccine-elicited MPER-directed antibodies have recently been reported from a human clinical trial. In this study, we sought to identify MPER-directed nAbs in simian immunodeficiency virus (SIV)-infected rhesus macaques. We isolated four lineages of SIV MPER-directed nAbs from two SIV-infected macaques.
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