We report on a temperature-, time-, and spectrally resolved study of the photoluminescence of type-I InP/ZnS colloidal nanocrystals with varying core size. By studying the exciton recombination dynamics we assess the exciton fine structure in these systems. In addition to the typical bright-dark doublet, the photoluminescence stems from an upper bright state in spite of its large energy splitting (∼100 meV). This striking observation results from dramatically lengthened thermalization processes among the fine structure levels and points to optical-phonon bottleneck effects in InP/ZnS nanocrystals. Furthermore, our data show that the radiative recombination of the dark exciton scales linearly with the bright-dark energy splitting for CdSe and InP nanocrystals. This finding strongly suggests a universal dangling bonds-assisted recombination of the dark exciton in colloidal nanostructures.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acsnano.5b07065 | DOI Listing |
Int J Biol Macromol
January 2025
Key Laboratory of Jianghuai Agricultural Product Fine Processing and Resource Utilization, Ministry of Agriculture and Rural Affairs, Anhui Engineering Research Center for High Value Utilization of Characteristic Agricultural Products, College of Tea & Food Science and Technology, Anhui Agricultural University, Hefei, China. Electronic address:
This study investigated the effect of different-polarity aqueous ethanol solutions on the formation of V-type starch originating from corn starch. Scanning electron microscopy revealed that the morphology of starch transformed from a random lamellar structure to a granular structure with decreasing solution polarity. When the ethanol concentration increased from 40 % to 60 %, the crystallinity and single-helix ratio of V-type starch increased from 9.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, D 69117 Heidelberg, Germany.
Calculations of the two-loop electron self-energy for the 1S Lamb shift are reported, performed to all orders in the nuclear binding strength parameter Zα (where Z is the nuclear charge number and α is the fine structure constant). Our approach allows calculations to be extended to nuclear charges lower than previously possible and improves the numerical accuracy by more than an order of magnitude. Extrapolation of our all-order results to hydrogen yields a result twice as precise as the previously accepted value [E.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA 15213.
The auditory system is unique among sensory systems in its ability to phase lock to and precisely follow very fast cycle-by-cycle fluctuations in the phase of sound-driven cochlear vibrations. Yet, the perceptual role of this temporal fine structure (TFS) code is debated. This fundamental gap is attributable to our inability to experimentally manipulate TFS cues without altering other perceptually relevant cues.
View Article and Find Full Text PDFBrief Bioinform
November 2024
Department of Computer Science, Hunan University, Changsha 410008, China.
Recently, the impressive performance of large language models (LLMs) on a wide range of tasks has attracted an increasing number of attempts to apply LLMs in drug discovery. However, molecule optimization, a critical task in the drug discovery pipeline, is currently an area that has seen little involvement from LLMs. Most of existing approaches focus solely on capturing the underlying patterns in chemical structures provided by the data, without taking advantage of expert feedback.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA.
Background: Alzheimer's disease (AD) hallmarks are amyloid plaques and tau tangles. APOE and TREM2 are the strongest genetic risk factors for AD. Triggering receptor expressed on myeloid cells 2 (TREM2) is increasingly recognized to play a central role in amyloid beta clearance and microglia activation in AD.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!