We report the fabrication and investigations of organic light-emitting diodes (OLEDs) using a composite made by mixing poly[2-methoxy-5(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) with CdSe/ZnS core/shell quantum dots (QDs). The electroluminescence efficiency of the studied devices was found to be improved as compared to devices using MEH-PPV. Moreover, the current density decreased with increasing QD concentration. We checked the effects of QDs on the electrical transport by determining the trap states, making use of the charge-based deep level transient spectroscopy (Q-DLTS) technique. The most striking result obtained is the decrease in trap density when adding QDs to the MEH-PPV polymer film. These results suggest that QDs would heal defects in nanocomposite-based devices and that CdSe/ZnS QDs prevent the trap center formation.
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http://dx.doi.org/10.1088/0957-4484/19/45/455202 | DOI Listing |
Chemistry
January 2025
University of Delaware, Chemistry and Biochemistry, UNITED STATES OF AMERICA.
We describe synthesis of BN-doped nanographene containing five phenylene units, boron and nitrogen atoms with both alternating ortho-disposition as well as direct B-N connection. Resulting BN doped nanographene exhibits blue fluorescence at 441 nm with extraordinary narrow fluorescence peak with full width at half maximum (FWHM) = 10-11 nm. Crystallography reveals supramolecular organization of this compound in the crystal phase.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea.
Photobiomodulation (PBM) is considered an effective and safe therapeutic modality in supporting the treatment of complications from a global pandemic-diabetes. In this study, PBM therapy is investigated to accelerate wound healing in diabetic mice (DM), under the combined biological effects of red light from a red organic light-emitting diode (ROLED) and near-infrared (NIR) light from an NIR conversion film (NCF) with dispersed CuInS/ZnS quantum dots (QDs). The QD concentration and the NCF structure were optimized to maximize the optical properties and mechanical stability.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Superhard Materials, Synergetic Extreme Condition High-Pressure Science Center, College of Physics, Jilin University, Changchun, China.
Metal-organic frameworks that feature hybrid fluorescence and phosphorescence offer unique advantages in white-emitting communities based on their multiple emission centers and high exciton utilization. However, it poses a substantial challenge to realize superior white-light emission in single-component metal-organic frameworks without encapsulating varying chromophores or integrating multiple phosphor subunits. Here, we achieve a high-performance white-light emission with photoluminescence quantum yield of 81.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
Understanding how structural modifications affect the photophysics of organic linkers is crucial for their integration into metal-organic frameworks (MOFs) for light-driven applications. This study explores the impact of varying the amine functional group position on two terephthalic acid derivatives─linker and linker ─by investigating their photophysics through a combination of steady-state and ultrafast laser spectroscopy and time-dependent density functional theory (TD-DFT) calculations. With tetrahydrofuran as the solvent, time-correlated single-photon counting revealed a 2-fold increase in the S excited-state lifetime of the molecule with the amine group at the meta position compared with that of the molecule with the amine group at the ortho position.
View Article and Find Full Text PDFChemistry
January 2025
Southern University of Science and Technology, Chemistry, 1088 Xueyuan Blvd., Xili, Nanshan District, 518055, Shenzhen, CHINA.
Poly(p-phenylenevinylene) (PPV) is a classic semiconducting π-conjugated polymers with outstanding optical and electronic properties, which shows important applications in the fields of optoelectronic, such as organic light-emitting diodes (OLEDs), organic solar cells (OSCs), and organic field-effect transistors (OFETs). In the working process of the device, the microstate of PPV decides its property. Therefore, it is significant to achieve ordered morphologies based on PPV at micro scale.
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