Synthesis of CdSe and CdTe Nanocrystals without Precursor Injection

Yang, Yongan; Wu, Huimeng; Williams, Kathryn R.; Cao, Y. Charles

doi:10.1002/anie.200502279

Cited by 393 publications

(429 citation statements)

References 20 publications

Supporting

Mentioning

411

Contrasting

Unclassified

Order By: Relevance

“…Semiconductor tetrapod synthesis : Nearly monodisperse zb-CdSe NCs were synthesized according to a previously reported method, [ 28 ] and used as seeds for tetrapod synthesis via the seeded growth approach, [ 12 ] with modifi cations. Briefl y, a mixture comprising of cadmium oxide (0.517 g), n-trioctylphosphine oxide (TOPO) (2.65 g), oleic acid (OA) (0.52 mL) and hexylphosphonic acid (HPA) (0.067 g) were degassed and then heated to 360 ° C under N 2 .…”

Section: Methodsmentioning

confidence: 99%

Low Threshold, Amplified Spontaneous Emission from Core‐Seeded Semiconductor Nanotetrapods Incorporated into a Sol–Gel Matrix

et al. 2012

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Low Threshold, Amplified Spontaneous Emission from Core‐Seeded Semiconductor Nanotetrapods Incorporated into a Sol–Gel Matrix

et al. 2012

View full text Add to dashboard Cite

“…Cadmium myristate can be synthesized as described in ref. [15] or prepared in situ by reacting 0.077 mg CdO with 0.29 g myristic acid in 5 mL 1-octadecene at 250 °C followed by the addition of 32 mL 1-octadecene and degassing the solution at 80°C under vacuum for 1 hr Preparation of stock solutions of w-CdSe and zb-CdSe seeds: The concentration of w-CdSe nanocrystals was calculated using the size dependent molar extinction coefficient given in refs. [31,33].…”

Section: Zinc Blende Cdse Nanocrystalsmentioning

confidence: 99%

“…These can be obtained by reacting cadmium and selenium precursors in the presence of the stabilizing agents trioctylphosphine oxide (TOPO), trioctylphosphine (TOP) and hexadecylamine (HDA) at high temperatures, typically above 300°C [1,13]. Recently CdSe nanocrystals with a cubic (zinc-blende) structure (further referred to as "zb-CdSe") have been synthesized by several groups [14][15][16]. In this work we compared w-CdSe and zb-CdSe nanocrystals for seeded growth of CdSe/CdS nano-hererostructures with different morphologies.…”

mentioning

confidence: 99%

Seeded Growth of Highly Luminescent CdSe/CdS Nanoheterostructures with Rod and Tetrapod Morphologies

et al. 2007

View full text Add to dashboard Cite

We have demonstrated that seeded growth of nanocrystals offers a convenient way to design nanoheterostructures with complex shapes and morphologies by changing the crystalline structure of the seed. By using CdSe nanocrystals with wurtzite and zinc blende structure as seeds for growth of CdS nanorods, we synthesized CdSe/CdS heterostructures nanorods and nano-tetrapods, respectively. Both of these structures showed excellent luminescent properties, combining high photoluminescence efficiency (~80% and ~50% for nanorods and nano-tetrapods, correspondingly), giant extinction coefficients (~2·10 7 M -1 cm -1 and ~1.5·10 8 M -1 cm -1 at 350 nm for nanorods and nano-tetrapods, correspondingly) and efficient energy transfer from the CdS arms into the emitting CdSe core. † Current address:

show abstract

“…During last two decades, formation of metal chalcogenide QDs has been investigated using various trialkylphosphine chalcogenides (R3P=E; E= S, Se, Te) as precursors. [13][14]29,49,[66][67][68] In this context, the chemical identity of an important selenium precursor, which is prepared by dissolving elemental selenium in ODE at high temperature (>180 o C) and used frequently in CdSe QD synthesis 40,52,[69][70][71] has not been resolved.…”

Section: Investigation Of Thementioning

confidence: 99%

Mechanistic Study of the Formation of Bright White Light-Emitting Ultrasmall CdSe Nanocrystals: Role of Phosphine Free Selenium Precursors

Dolai¹,

Dutta

Muhoberac³

et al. 2015

Chem. Mater.

View full text Add to dashboard Cite

ABSTRACT:We have designed a new non-phosphinated reaction pathway, which includes synthesis of a new, highly reactive Se-bridged organic species (chalcogenide precursor), to produce bright white light-emitting ultrasmall CdSe nanocrystals of high quality under mild reaction conditions. The detailed characterization of structural properties of the selenium precursor through combined 77 Se NMR and laser desorption ionization-mass spectrometry (LDI-MS) provided valuable insights into Se release and delineated the nanocrystal formation mechanism at the molecular level. The 1 H NMR study showed that the rate of disappearance of Se-precursor maintained a single-exponential decay with a rate constant of 2.3 x 10 -4 s -1 at room temperature. Furthermore, the combination of LDI-MS and optical spectroscopy was used for the first time to deconvolute the formation mechanism of our bright white light-emitting nanocrystals, which demonstrated initial formation of a smaller key nanocrystal intermediate (CdSe)19. Application of thermal driving force for destabilization resulted in (CdSe)n nanocrystal generation with n = 29-36 through continuous dissolution and addition of monomer onto existing nanocrystals while maintaining a living-polymerization type growth mode. Importantly, our ultrasmall CdSe nanocrystals displayed an unprecedentedly large fluorescence quantum yield of ~27% for this size regime (<2.0 nm diameter). These mixed oleylamine and cadmium benzoate ligand-coated CdSe nanocrystals showed a fluorescence lifetime of ~90 ns, a significantly large value for such small nanocrystals, which was due to delocalization of the exciton wavefunction into the ligand monolayer. We believe our findings will be relevant to formation of other metal chalcogenide nanocrystals through expansion of the understanding and manipulation of surface ligand chemistry, which together will allow the preparation of "artificial solids" with high charge conductivity and mobility for advanced solid-state device applications.3

show abstract

Synthesis of CdSe and CdTe Nanocrystals without Precursor Injection

Cited by 393 publications

References 20 publications

Low Threshold, Amplified Spontaneous Emission from Core‐Seeded Semiconductor Nanotetrapods Incorporated into a Sol–Gel Matrix

Low Threshold, Amplified Spontaneous Emission from Core‐Seeded Semiconductor Nanotetrapods Incorporated into a Sol–Gel Matrix

Seeded Growth of Highly Luminescent CdSe/CdS Nanoheterostructures with Rod and Tetrapod Morphologies

Mechanistic Study of the Formation of Bright White Light-Emitting Ultrasmall CdSe Nanocrystals: Role of Phosphine Free Selenium Precursors

Contact Info

Product

Resources

About