Defect engineering in perovskites has been found to be the most efficient approach to manipulate their performance in ultraviolet-to-visible photon conversion. Under UV irradiation, BaSnO exhibited multicolor photoluminescence (MCPL) in the bluish white region. Its origin has not been well studied in the literature and has been probed in this work using synchrotron radiation, positron annihilation and density functional theory. To achieve desirable performance of doped BaSnO in optoelectronics, it is imperative to have correct information on the dopant local site, doping induced defect evolution and efficacy of host to dopant energy transfer (HDET). Extended X-ray absorption fine structure (EXAFS) showed that Eu ions stabilize at both Ba and Sn sites consistent with the highly negative formation energy of around -6.26 eV. Eu doping leads to an intense D→F orange emission and a feeble D→F red emission and an internal quantum yield (IQY) of ∼21% mediated by ET from the defect level of Eu and Eu sites to the valence band maximum (VBM). X-ray absorption near edge structure (XANES) ruled out any role of Sn in the PL of BaSnO or Eu in the PL of BaSnO3:Eu. Interestingly, when co-doped, Eu stabilizes at Sn sites whereas La stabilizes at Ba sites with a formation energy value of -6.44 eV. Based on the asymmetry ratio in emission spectra, it was found that La ions lead to lowering of symmetry around Eu due to increased vacancies and structural distortions, and also suppress the luminescence IQY. We have performed experimental positron annihilation lifetime spectroscopy (PALS) to probe the defects in BaSnO in pristine samples and on doping/co-doping. The positron lifetimes for saturation trapping of positrons in various kinds of defects envisaged in BaSnO and in the defect free system were calculated using the MIKA Doppler program. Such deep insight into the effect of local structures, dopant sites, defect evolution, ET, etc. on the optical properties of BaSnO is expected to provide very deep insight for material scientists into the fabrication of perovskite-based optoelectronic and light-emitting devices.
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http://dx.doi.org/10.1039/d1cp02349g | DOI Listing |
Acc Chem Res
January 2025
Helmholtz Institute Ulm (HIU) Electrochemical Energy Storage, Helmholtzstrasse 11, 89081 Ulm, Germany.
ConspectusLithium-ion batteries (LIBs) based on graphite anodes are a widely used state-of-the-art battery technology, but their energy density is approaching theoretical limits, prompting interest in lithium-metal batteries (LMBs) that can achieve higher energy density. In addition, the limited availability of lithium reserves raises supply concerns; therefore, research on postlithium metal batteries is underway. A major issue with these metal anodes, including lithium, is dendritic formation and insufficient reversibility, which leads to safety risks due to short circuits and the use of flammable electrolytes.
View Article and Find Full Text PDFSci Rep
January 2025
Institute of Animal Reproduction and Food Research, Polish Academy of Sciences in Olsztyn, 10-748, Olsztyn, Poland.
Mares with endometrosis exhibit histological changes not only in the endometrium but also in the myometrium that suggest possible functional impairment. The molecular background of these changes is not well understood. We hypothesize that the transcriptomic profile of the mare myometrium varies depending on the degree of endometrosis in mares.
View Article and Find Full Text PDFSci Rep
January 2025
Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, 622 West 168th Street, Ste. 876, New York, NY, 10032, USA.
The COVID-19 pandemic may have exacerbated mental health conditions by introducing and/or modifying stressors, particularly in university populations. We examined longitudinal patterns, time-varying predictors, and contemporaneous correlates of moderate-severe psychological distress (MS-PD) among college students. During 2020-2021, participants completed self-administered questionnaires quarterly (T1 = 562, T2 = 334, T3 = 221, and T4 = 169).
View Article and Find Full Text PDFNat Commun
January 2025
Center for High Pressure Science, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, 066004, China.
Hydrous aluminosilicates are important deep water-carriers in sediments subducting into the deep mantle. To date, it remains enigmatic how hydrous aluminosilicates withstand extremely high temperatures in the mantle transition zone. Here we systematically investigate the crystal structures and chemical compositions of typical hydrous aluminosilicates using single-crystal X-ray diffraction, electron probe microanalyzer, and nanoscale secondary ion mass spectrometry.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an, 710049, China. Electronic address:
Background: Plasmonic core-shell nanostructures with embedded internal markers used as Raman probes have attracted great attention in surface-enhanced Raman scattering (SERS) immunoassay for cancer biomarkers due to their excellent uniform enhancement. However, current core-shell nanostructures typically exhibit a spherical shape and are coated with a gold shell, resulting in constrained local field enhancement.
Results: In this work, we prepared a core-shell AuNR@BDT@Ag structure by depositing silver on the surface of Raman reporter-modified gold nanorods (AuNR).
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