A great step forward in science and technology was made when it was discovered that lattice mismatch can be used to grow highly ordered, artificial atom-like structures called self-assembled quantum dots. Several groups have in the meantime successfully demonstrated useful infrared photodetection devices which are based on this technology. The new physics is fascinating, and there is no doubt that many new applications will be found when we have developed a better understanding of the underlying physical processes, and in particular when we have learned how to integrate the exciting new developments made in nanoscopic addressing and molecular self-assembly methods with semiconducting dots. In this paper we examine the scientific and technical questions encountered in current state of the art infrared detector technology and suggest ways of overcoming these difficulties. Promoting simple physical pictures, we focus in particular on the problem of high temperature detector operation and discuss the origin of dark current, noise, and photoresponse.
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http://dx.doi.org/10.1088/0957-4484/16/2/007 | DOI Listing |
Chem Commun (Camb)
January 2025
College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang 550025, China.
In this study, MAPbBr was encapsulated within a porous metal-organic framework (CAU-17) ligand-assisted reprecipitation, which enhanced the perovskite's photocatalytic stability. This encapsulation approach not only stabilises the photocatalytic performance of MAPbBr but also enables further enhancement of its catalytic efficiency through halogen anion group modification. Results from various characterisation demonstrate that the CAU-17/MAPbBrCl composites possess excellent properties, achieving a tetracycline degradation efficiency of up to 92%.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
Department of Materials Science and Engineering, and Centre for Functional Photonics (CFP), City University of Hong Kong, Hong Kong SAR 999077, P. R. China.
Bioimaging probes based on carbon dots (CDs) can become a useful replacement for existing commercial probes, benefiting clinical diagnostics. While the development of dual-mode CD-based probes for magnetic resonance imaging (MRI), which provides the ability for photoluminescence (PL) detection at the same time, is ongoing, several challenges have to be addressed. First, most of the CD-based probes still emit at shorter wavelengths (blue/green spectral range), which is harmful to biological objects or have very low PL intensity in the biological window of tissue transparency (red/near-infrared spectral range).
View Article and Find Full Text PDFAnal Chem
January 2025
Clinical Medical Center of Tissue Engineering and Regeneration, Xinxiang Medical University, Xinxiang 453003, P. R. China.
The development of sophisticated nanomaterials with synergistically enhanced functionalities and applications has been greatly promoted via the construction of Janus nanoparticles with controlled compositions. In this work, we described and demonstrated the formation of Janus Au-PbS nanoparticles (NPs) by Au NPs-mediated spontaneous epitaxial nucleation and growth. The mechanism of formation of Janus Au-PbS NPs was investigated in detail.
View Article and Find Full Text PDFFood Chem
January 2025
Department of Food Science and Technology, College of Agriculture, Isfahan University of Technology, Isfahan 84156-83111, Iran. Electronic address:
A colorimetric-fluorescence ripeness indicator, based on copper nanoparticles and carbon quantum dots doped with nitrogen (CuNPs/N@CQD) immobilized in agar hydrogel (AGH-CuNPs/N@CQDs) for ethylene gas detection, was developed for detecting the ripening of bananas. Ethylene could reduce the fluorescence intensity of CuNPs/N@CQDs and cause a red shift of the LSPR peak. The prepared AGH-CuNPs/N@CQDs indicator had an irreversible response to ethylene with LOD and LOQ of 9.
View Article and Find Full Text PDFAnal Chem
January 2025
The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai 200234, China.
Conventional dual-signal electrochemiluminescence (ECL) sensors feature high sensitivity and reliability, but the involvement of coreactants inevitably results in a complex configuration and shows reproducibility risk. Here, we propose an exogenous coreactant-free dual-signal platform, comprising luminol (anodic luminophore), CdSe quantum dots (cathodic luminophore), and CoO/TiC electrocatalyst (coreaction promoter). At different redox potentials, CoO/TiC induces water oxidation and oxygen reduction to produce OH and O radicals, which subsequently drive cathodic and anodic ECL emission, respectively.
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