On ultrasmall nanocrystals

McBride, James R.; Dukes, Albert D.; Schreuder, Michael A.; Rosenthal, Sandra J.

doi:10.1016/j.cplett.2010.08.052

Cited by 71 publications

(91 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…(McBride et al 2010;Kim et al 2014). Recent studies on the mechanism and dynamics of the photoluminescence (PL) of ultrasmall cadmium chalcogenide NPs (McBride et al 2010;Dukes et al 2011;Zhou et al 2011;Pennycook et al 2012;Rosson et al 2012), especially those performed on single NPs (Dukes et al 2011;Pennycook et al 2012), showed that the large spectral width of the PL band and relatively long PL life-time is not the result of the collective properties of an inhomogeneous NP ensemble but rather of inherent properties of each individual NP. These findings shed light and stimulated further discussions also on the PL mechanism in larger, ''regular'' NPs.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and luminescent properties of ultrasmall colloidal CdS nanoparticles stabilized by Cd(II) complexes with ammonia and mercaptoacetate

et al. 2014

View full text Add to dashboard Cite

The synthesis of stable water-soluble ultrasmall 1.8 nm CdS nanoparticles co-stabilized with Cd(II) complexes with NH 3 and mercaptoacetate ions is reported. The CdS nanoparticles emit broadband photoluminescence with a peak at 2.3 eV and a quantum yield of up to 15 %. The photoluminescence decay is strongly non-exponential and characterized by an average radiative life-time increasing from 46 to 105 ns as the emission quantum energy decreases from 2.9 to 1.8 eV. The photoluminescence intensity and life-time decrease to about 50 % as the colloid temperature is elevated from 22 to 50°C. This behavior is completely reversible and assumed to originate from the thermally activated dissociation of Cd(II)-NH 3 complexes on the nanoparticle surface and the formation of Cd(II)-H 2 O complexes acting as the radiationless recombination sites. The strong temperature dependence of the luminescent properties coupled with the small size and reasonably high quantum yields of emission makes CdS nanoparticles co-stabilized with NH 3 and mercaptoacetate attractive for bio-imaging, bio-sensing, and other applications.

show abstract

Section: Introductionmentioning

confidence: 99%

Synthesis and luminescent properties of ultrasmall colloidal CdS nanoparticles stabilized by Cd(II) complexes with ammonia and mercaptoacetate

et al. 2014

View full text Add to dashboard Cite

show abstract

“…[38] The determination of the size of ultrasmall CdSe nanoparticle using tunnelling microscopy exposed to large margin error due to the very poor contrast. [39] Often local probes, such as high-resolution transmission electron microscopy (HRTEM) are used, but sometimes it is difficult to obtain accurate results on the average particle diameter or on the internal structure due to problems with sampling or poor contrast. The small-angle X-ray scattering (SAXS) analysis gives information about the shape and size of nanoparticles with good precision but contains no information about the atomic structure.…”

Section: Nanoparticle Size From Pdf Analysis: the Size Of Crystallinementioning

confidence: 99%

“…This obtained information is not available from some alternative conventional nano-techniques such as TEM. [39] Using this methodology, Yang et al [40] detected 'considerably enhanced compressive homogeneous strain and increased inhomogeneous strain in the bond-length distribution' of the first PDF peak, the latter reflecting the observed disorder of the ultrasmall nanoparticles. [40] This method is generally applicable to the characterisation of the nanostructured materials, many of which may exhibit complex structure.…”

Section: Introductionmentioning

confidence: 99%

Total scattering atomic pair distribution function: new methodology for nanostructure determination

Masadeh

2016

Journal of Experimental Nanoscience

View full text Add to dashboard Cite

The conventional X-ray diffraction (XRD) methods probe for the presence of long-range order towards a solution of the average crystal structure. Experimentally, structural information about longrange, periodic atomic ordering is reflected in the Bragg scattering while local atomic structural deviations from the average structure mainly affect the diffuse scattering intensities. In order to obtain structural information about both average and local atomic structures, a technique that takes in account both Bragg and diffuse scattering needs to be employed, such as the total scattering atomic pair distribution function (PDF) technique. This article introduces a PDF-based methodology that can be applied to extract precise structural information about nanoparticles such as the size of the crystalline core region, the degree of crystallinity, the atomic structure of the core region, local bonding, and the degree of the internal disorder, as a function of the nanoparticle diameter. This article sheds light on a new PDF-based methodology that can yield precise quantitative structural information about small nanocrystals from XRD data, and also describes the essential aspects of this proposed methodology as well as its great potential. This method is generally applicable to the characterisation of the nanoscale solid, many of which may exhibit complex disordered structure.

show abstract

“…Magic sized clusters of cadmium selenide have been documented in numerous recent reports and are believed to play crucial roles in nanocrystal synthesis, 1–11 including as a solute reservoir for larger nanocrystals and as building blocks for the assembly of sheet and ribbon structures. 1, 12 Many of these studies report a cluster with lowest energy absorption near 420 nm.…”

mentioning

confidence: 99%

Tuning the Surface Structure and Optical Properties of CdSe Clusters Using Coordination Chemistry

Cossairt

Juhás

Billinge

et al. 2011

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

A series of nonstoichiometric CdSe clusters with lowest energy electronic absorptions between 409 – 420 nm has been prepared from cadmium 1-naphthoate, 2-naphthoate, 4-thiomethyl-1-naphthaote, and 1-naphthalene thiolate complexes and diphenylphosphine selenide (DPPSe). Pair distribution function analysis of X-ray diffraction data, ligand exchange experiments, and NMR molecular weight analyses suggest the nanocrystal core changes minimally among these clusters despite significant changes to their absorption and luminescence spectra. Photoluminescence excitation spectra obtained at 77 K reveal an energy transfer process between the surface-trapped excited state and the naphthalene-containing ligands that leads to ligand phosphorescence. A Dexter energy transfer mechanism is proposed to explain the observation of ligand phosphorescence on excitation of the cluster. These compounds demonstrate that cluster absorption and trap luminescence can be controlled with surface coordination chemistry.

show abstract

On ultrasmall nanocrystals

Cited by 71 publications

References 58 publications

Synthesis and luminescent properties of ultrasmall colloidal CdS nanoparticles stabilized by Cd(II) complexes with ammonia and mercaptoacetate

Synthesis and luminescent properties of ultrasmall colloidal CdS nanoparticles stabilized by Cd(II) complexes with ammonia and mercaptoacetate

Total scattering atomic pair distribution function: new methodology for nanostructure determination

Tuning the Surface Structure and Optical Properties of CdSe Clusters Using Coordination Chemistry

Contact Info

Product

Resources

About