Metal halide perovskites have excellent optoelectronic properties. This study aims to determine how the optoelectronic properties of a model perovskite, cesium lead bromide (CsPbBr), change with length and thickness in one dimension (1D). By examining the photophysics of CsPbBr quantum dots (QDs), nanowires (NWs), and nanorods (NRs), we observe the influence of confinement, exciton diffusion, and trapping on their optical properties. Our findings reveal that exciton diffusion to trap states limits the photoluminescence quantum yield (PLQY) of 1D CsPbBr in the weakly confined regime (8-14 nm) and explains their long-lived exciton dynamics, while enhanced radiative rates contribute to achieving near-unity PLQY in the strongly confined regime (<7 nm). Consequently, blue-emitting, 2.4 nm-thick CsPbBr NRs were 3.6X more emissive than the conventional CsPbBr QDs. This study underscores how structural optimization can improve the optoelectronic performance of CsPbBr and provides insight into the complex interplay of radiative and nonradiative processes in 1D ionic semiconductors.
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http://dx.doi.org/10.1021/jacs.4c18320 | DOI Listing |
ACS Appl Mater Interfaces
March 2025
State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou 510640, P. R. China.
The relationship between the structure and function of condensed matter is complex and changeable, which is especially suitable for combination with machine learning to quickly obtain optimized experimental conditions. However, little research has been done on the effect of temperature on condensed matter and how it affects device performance because the difference between the in situ physical property parameters (which are lowered by the surface tension and mixing entropy) and the basic parameters of the bulk makes accurate AI predictions difficult. In this work, P3HT/ITIC was chosen as the donor/acceptor material for the active layer of organic phototransistors (OPTs).
View Article and Find Full Text PDFTalanta
March 2025
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, 130000, PR China. Electronic address:
Methods for electrochemical detection of heavy metal ions have garnered widespread attention due to their high sensitivity, ease of operation, low cost, and suitability for on-site detection. However, these methods typically require a pre-enrichment step to improve the detection limit and sensitivity, which increases operational complexity and introduces potential errors. In this study, tungsten oxide electrodes with various functional groups were prepared by electrodeposition and high-temperature annealing, utilizing the amphoteric properties of l-alanine.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
March 2025
Anhui Province Key Laboratory of Optoelectronic and Magnetism Functional Materials, School of Chemistry and Chemical Engineering, Anqing Normal University, Anqing 246011, China.
Hypercrosslinked polymers (HCPs) are the most promising porous organic polymers for large-scale production due to their easy preparation, extensive raw material source, good stability, and large specific surface area. However, due to the lack of extended conjugability, their application in fluorescence sensing is limited. Herein, three conjugated hypercrosslinked polymers (the conjugated HCPs: TPPDA-DMB, TDPAB-DMB, and MTDAB-DMB) were easily prepared by the Friedel-Craft arylation reactions with phenylenediamine or phenylenetriamine derivatives and p-dimethoxybenzene (DMB).
View Article and Find Full Text PDFJ Am Chem Soc
March 2025
Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.
Metal halide perovskites have excellent optoelectronic properties. This study aims to determine how the optoelectronic properties of a model perovskite, cesium lead bromide (CsPbBr), change with length and thickness in one dimension (1D). By examining the photophysics of CsPbBr quantum dots (QDs), nanowires (NWs), and nanorods (NRs), we observe the influence of confinement, exciton diffusion, and trapping on their optical properties.
View Article and Find Full Text PDFNanoscale
March 2025
School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510640, China.
Raman spectroscopy has demonstrated significant potential in molecular detection, analysis, and identification, particularly when it adopts single-molecule surface-enhanced Raman scattering (SM-SERS) substrates. A recent SM-SERS scheme incorporates two-fold Raman enhancement mechanisms: the electromagnetic enhancement enabled by a plasmonic nanogap hotspot formed from gold sphere nanoparticles sitting on a gold mirror and the chemical enhancement enabled by a two-dimensional material, WS, inserted into the nanogap. In this work we integrate multiple advanced concepts and techniques to achieve remarkable performance improvements of SM-SERS.
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