We present an analysis of positron lifetimes in solids with unprecedented depth. Instead of modeling correlation effects with density functionals, we study positron-electron wave functions with long-range correlations included. This gives new insight in understanding positron annihilation in metals, insulators, and semiconductors. By using a new quantum Monte Carlo approach for computation of positron lifetimes, an improved accuracy compared to previous computations is obtained for a representative set of materials when compared with experiment. Thus, we present a method without free parameters as a useful alternative to the already existing methods for modeling positrons in solids.
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http://dx.doi.org/10.1103/PhysRevLett.129.166403 | DOI Listing |
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January 2025
Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, P. R. China.
Near-infrared light response catalysts have received great attention in renewable solar energy conversion, energy production, and environmental purification. Here, near-infrared photodegradation is successfully achieved in rare earth single atom anchored NaYF@g-CN heterojunctions by the synergistic effect of Z-scheme heterojunction and antenna of rare earth single atoms. The UV-vis light emitted by Tm can not only be directly absorbed by g-CN to generate electron-hole pairs, realizing efficient energy transfer, but also be absorbed by NaYF substrate, and generating photo-generated electrons at its impurity level, transferring the active charge to the valence band of g-CN, forming a Z-scheme heterojunction and further improving the photocatalytic efficiency.
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January 2025
Key Lab of Marin Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, P. R. China.
Altering the generation route of reactive species is a potent means to augment the photocatalytic activity. In this study, MoS/MIL-101(Fe) S-scheme heterojunction (MF2) is prepared using a water/solvent thermal method for photocatalytic degradation of chlorsulfuron. Driven by the internal electric field, the local electron density of MF2 is redistributed, thus enhancing the adsorption of O.
View Article and Find Full Text PDFMed Phys
January 2025
Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Kraków, Poland.
Background: Total-body (TB) Positron Emission Tomography (PET) is one of the most promising medical diagnostics modalities, opening new perspectives for personalized medicine, low-dose imaging, multi-organ dynamic imaging or kinetic modeling. The high sensitivity provided by total-body technology can be advantageous for novel tomography methods like positronium imaging, demanding the registration of triple coincidences. Currently, state-of-the-art PET scanners use inorganic scintillators.
View Article and Find Full Text PDFNanoscale Adv
January 2025
Université de Lorraine, CNRS, LRGP F-54000 Nancy France
Water-dispersible core/shell CuInZnSe/ZnS (CIZSe/ZnS) quantum dots (QDs) were efficiently synthesized under microwave irradiation using -acetylcysteine (NAC) and sodium citrate as capping agents. The photoluminescence (PL) emission of CIZSe/ZnS QDs can be tuned from 593 to 733 nm with varying the Zn : Cu molar ratio in the CIZSe core. CIZSe/ZnS QDs prepared with a Zn : Cu ratio of 0.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Department of Chemistry, Key Laboratory of Advanced Energy Material Chemistry, Frontiers Science Center for New Organic Matter, State Key Laboratory of Advanced Chemical Power Sources, College of Chemistry, Nankai University, Tianjin, 300071, P. R. China.
Localized surface plasmon resonance (LSPR) metals exhibit remarkable light-absorbing property and unique catalytic activity, attracting significant attention in photocatalysts recently. However, the practical application of plasmonic nanometal is hindered by challenge of energetic electrons extraction and low selectivity. The energetic carriers generated in nanometal under illumination have extremely short lifetimes, leading to rapid energy loss.
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