The photoluminescence emission of nanoporous anodic aluminum oxide films formed in phosphoric acid is studied in order to explore their defect-based subband electronic structure. Different excitation wavelengths are used to identify most of the details of the subband states. The films are produced under different anodizing conditions to optimize their emission in the visible range. Scanning electron microscopy investigations confirm pore formation in the produced layers. Gaussian analysis of the emission data indicates that subband states change with anodizing parameters, and various point defects can be formed both in the bulk and on the surface of these nanoporous layers during anodizing.
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http://dx.doi.org/10.1186/1556-276X-7-689 | DOI Listing |
R Soc Open Sci
January 2025
Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt.
Carbon quantum dots (CQDs) are a recently developed class of fluorescent nanoparticles made from carbon. Co-doping with heteroatoms such as nitrogen and sulfur improved the properties and generated a high quantum yield. In the proposed study, we utilized a simple, cost-effective, single-stage hydrothermal approach to produce extreme photoluminescence co-doped, nitrogen and sulfur, CQDs (N,S-CODs).
View Article and Find Full Text PDFLuminescence
January 2025
Vlokh Institute of Physical Optics, Ivan Franko National University of Lviv, Lviv, Ukraine.
Spectroscopic properties of Tb-doped and Tb-Ag codoped lithium tetraborate (LTB) glasses with LiBO (or LiO-2BO) composition are investigated and analysed using electron paramagnetic resonance (EPR), optical absorption, photoluminescence (PL) and photoluminescence excitation (PLE) spectra, PL decay kinetics and absolute quantum yield (QY) measurements. PL spectra of the investigated glasses show numerous narrow emission bands corresponding to the D → F (J = 6-0) and D → F (J = 5-3) transitions of Tb (4f) ions. The most intense PL band of Tb ions at 541 nm (D → F transition) is characterised by a lifetime slightly exceeding 2.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Tsinghua University, Chemistry, HeTian Building Dept. of Chemistry, Tsinghua University, Beijing, P. R. China, 100084, Beijing, CHINA.
Expanded heterohelicene composing of alternating linearly and angularly fused multi-resonance (MR) skeleton has garnered wide interest for their promising narrowband emission. Herein, a pair of sym- and asym-expanded heterohelicene isomers are firstly developed by merging boron/oxygen (B/O)-embedded MR triangulene and indolo[3,2,1-jk]carbazole units via one-shot synthesis. Owing to the fully resonating extended helical skeleton, the target heterohelicenes exhibit significantly narrowed spectra bandwidth while emission red-shifting, thus affording deep-blue narrowband emission with peak at around 460 nm, full-width-at-half-maximum (FWHM) of merely 18 nm and near-unity photoluminescence quantum yields.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Chemistry, Career Point University, Hamirpur Campus, H.P., India; CNST, Career Point University, Hamirpur Campus, H.P., India. Electronic address:
In our study, we have tried to enhance the biological qualities of nickel oxide nanoparticles and nanocomposites which were prepared using the extract of Aegle marmelos tree leaves and chitosan biopolymer. For in-depth study of the fabricated samples, numerous physiochemical approaches were utilized. The analysis used consists of field emission scanning electron microscopy with energy dispersive X-ray analysis and photoluminescence, X-ray diffraction, UV-visible spectroscopy, and Fourier transform infrared spectroscopy.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Oxford University: University of Oxford, Department of Chemistry, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
Organic semiconducting polymers play a pivotal role in the development of field-effect transistors (OFETs) and organic light-emitting diodes (OLEDs), owing to their cost-effectiveness, structural versatility, and solution processability. However, achieving polymers with both high charge carrier mobility (μ) and photoluminescence (PL) quantum yield (Φ) remains a challenge. In this work, we present the design and synthesis of a novel donor-acceptor π-conjugated polymer, TTIF-BT, featuring a di-Thioeno[3,2-b] ThioenoIndeno[1,2-b] Fluorene (TTIF) backbone as the donor component.
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