Seeded growth of InP and InAs quantum rods using indium acetate and myristic acid

Shweky, Itzhak; Aharoni, Assaf; Mokari, Taleb; Rothenberg, Eli; Nadler, Moshe; Popov, Inna; Banin, Uri

doi:10.1016/j.msec.2005.09.040

Cited by 22 publications

(17 citation statements)

References 30 publications

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“…Low melting catalysts can therefore be obtained from nanometer-sized particles of common VLS elements. While successfully used by Banin et al 74 to make InP and InAs nanorods using Au NPs, the resulting structures lack the long aspect ratios of nanowires. Our initial attempts at NW growth likewise focused on the use of small 1.5 nm diameter Au particles with an estimated melting point of B370 1C.…”

Section: Solution-liquid-solid (Sls) Growthmentioning

confidence: 99%

An overview of solution-based semiconductor nanowires: synthesis and optical studies

Kuno

2008

Phys. Chem. Chem. Phys.

163

197

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This Perspective describes recent progress in the synthesis and optical characterization of high quality solution-based semiconductor nanowires (NWs). The described solution-phase NW syntheses are analogous to conventional vapor-liquid-solid (VLS) growth schemes for 1D materials. However, a primary difference is that low melting catalyst particles are used to induce the asymmetric crystallization of wires at temperatures sustainable by solution chemistry (T < 400 degrees C). Reactions are conducted in the presence of mild coordinating solvents such as trioctylphosphine oxide, which modulate NW growth kinetics and passivate their surfaces. This approach borrows from concurrent advances in colloidal quantum dot (QD) syntheses. In particular, the appropriate choice of solvent, coordinating ligands, growth conditions and precursors all originate from existing preparations for high quality semiconductor QDs. Subsequent structural characterization of the nanowires reveals their high degree of crystallinity, low ensemble size distributions and intrawire uniformity. Variations of these syntheses yield branched CdSe, CdTe and PbSe NWs with characteristic tripod, v-shape, y-shape, t-shape and "higher order" morphologies. A "geminate" NW nucleation mechanism is used to explain this phenomenon. The proposed branching model is also predictive and can be tested by additional nanowire syntheses that we or others conduct. Corresponding optical properties of both straight and branched wires are described, including measurements of their frequency-dependent absorption cross sections. Preliminary ensemble experiments focus on transient differential absorption measurements to study relevant carrier relaxation pathways and timescales over which these processes occur. Additional studies reveal intrawire optical heterogeneity and fluorescence intermittency at the single NW level.

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Section: Solution-liquid-solid (Sls) Growthmentioning

confidence: 99%

An overview of solution-based semiconductor nanowires: synthesis and optical studies

Kuno

2008

Phys. Chem. Chem. Phys.

163

197

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“…T he degree of ligand ordering on colloidal inorganic nanocrystal surfaces has long been a topic of interest [1][2][3][4][5][6][7][8] . Capping ligands are chemically essential, providing protection against aggregation and contributing significantly to solubility 4,9,10 . Kinetic and thermodynamic properties of the nanocrystals are also greatly influenced by ligands [7][8][9][10] .…”

mentioning

confidence: 99%

“…Capping ligands are chemically essential, providing protection against aggregation and contributing significantly to solubility 4,9,10 . Kinetic and thermodynamic properties of the nanocrystals are also greatly influenced by ligands [7][8][9][10] . There are reports of the degree of ordering led by theoretical works 2,3 and extending to indirect probes, such as infrared spectroscopy 5,11 , small angle X-ray scattering of interparticle spacing 11,12 , and calorimetric measurements that infer entropy 5,7,8,11,12 .…”

mentioning

confidence: 99%

“…More surface-sensitive GIWAXS measurements of superlattices of lead sulfide and cadmium selenide quantum dots show a similar peak [13][14][15] . Explanations include unique alloys at the quantum dot surfaces 16,17 , amorphous glass slides 18,19 , oxide formation 9,10 , forbidden reflections 20,21 , and unreacted organic precursors such as indium myristate and lead oleate 22,23 . Most reports opt to ignore this peak entirely, either with a lack of explanation or failing to include it in the reported spectrum [13][14][15]24,25 .…”

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confidence: 99%

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Observation of ordered organic capping ligands on semiconducting quantum dots via powder X-ray diffraction

et al. 2021

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Powder X-ray diffraction is one of the key techniques used to characterize the inorganic structure of colloidal nanocrystals. The comparatively low scattering factor of nuclei of the organic capping ligands and their propensity to be disordered has led investigators to typically consider them effectively invisible to this technique. In this report, we demonstrate that a commonly observed powder X-ray diffraction peak around $$q=1.4{\AA}^{-1}$$ q = 1.4 Å − 1 observed in many small, colloidal quantum dots can be assigned to well-ordered aliphatic ligands bound to and capping the nanocrystals. This conclusion differs from a variety of explanations ascribed by previous sources, the majority of which propose an excess of organic material. Additionally, we demonstrate that the observed ligand peak is a sensitive probe of ligand shell ordering. Changes as a function of ligand length, geometry, and temperature can all be readily observed by X-ray diffraction and manipulated to achieve desired outcomes for the final colloidal system.

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“…[13][14] However the scenario is significantly different when the semiconductor growth takes place in solution through the analogous SLS approach, [11][12] since the reaction temperatures reached are well below those used in the vapor phase and thus Au (T m = 1,064 °C) can hardly melt. While for the formation of Si, Ge or InP elongated NCs in solution Au nanoparticles still show an efficient catalytic performance, [16][17][18][19] this is not so clear in the case of Cd chalcogenide 1D nanostructures. Bismuth is generally used to catalyze the growth of Cdbased semiconductors by SLS mechanisms due to its lower melting point (T m = 271 °C).…”

Section: Introductionmentioning

confidence: 98%

Au-Assisted Growth of Anisotropic and Epitaxial CdSe Colloidal Nanocrystals via in Situ Dismantling of Quantum Dots

Fernàndez-Altable¹,

Dalmases²,

Falqui

et al. 2015

Chem. Mater.

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Metallic nanocrystals have revealed in the last years as valuable materials for the catalytic growth of semiconductor nanowires. Yet, only low melting point metals like Bi have been reported to successfully assist the growth of elongated CdX (X = S, Se, Te) systems in solution, and the possibility to use plasmonic noble metals has become a challenging task. In this work we show that the growth of anisotropic CdSe nanostructures in solution can also be efficiently catalyzed by colloidal Au nanoparticles, following a preferential crystallographic alignment between the metallic and semiconductor domains. Noteworthy, we report the heterodox use of semiconductor quantum dots as an homogeneous and tunable source of reactive monomer species to the solution. The mechanistic studies reveal that the in-situ delivery of these cadmium and chalcogen monomer species and the formation of Au x Cd y alloy seeds are both key factors for the epitaxial growth of elongated CdSe domains. The implementation of this method suggests an alternative synthetic approach for the assembly of different semiconductor domains into more complex heterostructures.

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Seeded growth of InP and InAs quantum rods using indium acetate and myristic acid

Cited by 22 publications

References 30 publications

An overview of solution-based semiconductor nanowires: synthesis and optical studies

An overview of solution-based semiconductor nanowires: synthesis and optical studies

Observation of ordered organic capping ligands on semiconducting quantum dots via powder X-ray diffraction

Au-Assisted Growth of Anisotropic and Epitaxial CdSe Colloidal Nanocrystals via in Situ Dismantling of Quantum Dots

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