Colloidal synthesis of CuGaS x Se 2 − x nanoribbons mediated by Cu 1.75 (SSe) nanocrystals as catalysts (original) (raw)
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Synthesis of Colloidal CuGaSe 2 , CuInSe 2 , and Cu(InGa)Se 2 Nanoparticles
Chemistry of Materials, 2008
We synthesize CuGaSe 2 , CuInSe 2 , and Cu(InGa)Se 2 nanoparticles in oleylamine with narrow size distribution using commercial grade copper, indium, gallium salts, and Se powder. Tunable nanoparticle size and composition are achieved through manipulation of reaction temperature and precursor concentrations. Ternary and quaternary materials are engineered by the judicious matching of ligand-precursor reactivities.
Colloidal Preparation of CuInSe2, CuGaSe2 and CIGS Nanoparticles
CuInSe 2 , CuGaSe 2 and CuIn (1Àx) Ga x Se 2 (CIGS) nanoparticles were synthesised from the diisopropyldiselenophosphinatometal complexes M x [ i Pr 2 PSe 2 ] n (M ¼ Cu(I), In(III), Ga(III); n ¼ 1, 3) by thermal decomposition of the precursors in HDA/TOP at 120-210 C or 250 C. The semiconductor nanoparticles obtained were characterized by powder X-ray diffraction (p-XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) analysis. The diameters of the nanoparticles for CuInSe 2 , CuGaSe 2 and CuIn 0.7 Ga 0.3 Se 2 were found to be 4.9 AE 0.6 nm (at 180 C), 13.5 AE 2.9 nm (at 250 C) and 14 AE 2.22 nm (at 250 C) respectively. The p-XRD patterns for the nanoparticulate samples were assigned to the corresponding ICDD patterns for tetragonal chalcopyrite phase.
Synthesis of 1D Cu2S with tailored morphology via single and mixed ionic surfactant templates
Materials Chemistry and Physics, 2004
Using a simple surfactant-assisted pathway, various shapes of crystalline copper sulphide (Cu 2 S) such as micro and submicron particles, nanorods and nanowires have been synthesized. This type of shape tailoring was possible by varying the molar ratio of cationic and anionic surfactants. Under appropriate condition, uniform nanowires were obtained. This was revealed from scanning and transmission electron microscopy. XRD analysis confirms the formation of monoclinic Cu 2 S. The optical band gap determined from reflectance spectra was found to have values within the range of 1.22-1.24 eV. The aspect ratio of the nanorods was found to increase with the increase of the concentration of anionic surfactant. .in (S. Chaudhuri). work is two-fold: (a) possibilities of shape tailoring and (b) attempts to understand the role of the surfactants individually and collectively.
Systematic Study into the Synthesis and Shape Development in Colloidal CuInxGa1–xS2 Nanocrystals
Herein, we report a systematic study on the colloidal growth of CuIn x Ga 1−x S 2 nanocrystals and nanorods. The formation of CuIn x Ga 1−x S 2 nanocrystals is shown to occur in several discrete steps, beginning with formation of the binary copper sulfide, transitioning through ternary and subsequently progressing to yield the quaternary form. This allows fine-tuning of the aspect ratio through incorporation of amine ligands of differing alkyl chain length giving nanorods ranging from ∼7.5 to 14 nm in diameter. The complexity of this system is extensively detailed with a sequential investigation of the effect of amines, thiols, phosphonic acids, in addition to coordinating and noncoordinating solvents on growth protocols. A diverse range of shape morphologies is attained, ranging from hexagon discs to hatchet shaped crystals, with an optimal synthetic window demonstrated using thiol-amine ligands to generate regular nanorods of controlled dimensions. These nanorods can be assembled over large-scale areas with each nanorod vertically aligned and close packed, allowing for device scale properties defined by the aspect ratio of each building block.
Chemistry of Materials, 2013
We report a phosphine-free colloidal synthesis of CuIn x Ga 1−x S 2 (CIGS) nanocrystals (NCs) by heating a mixture of metal salts, elemental sulfur, octadecene, and oleylamine. In contrast with the more commonly used hot injection, this procedure is highly suitable for large-scale NC production, which we tested by performing a gram-scale synthesis. The composition of the CIGS NCs could be tuned by varying the In and Ga precursor ratios, and the samples showed a composition-dependent band gap energy. The average particle size was scaled from 13 to 19 nm by increasing the reaction temperature from 230 to 270°C. Two concomitant growth mechanisms took place: in one, covellite (CuS) NCs nucleated already at room temperature and then incorporated increasing amounts of In and Ga until they evolved into chalcopyrite CIGS NCs. In the second mechanism, CIGS NCs directly nucleated at intermediate temperatures. They were smaller than the NCs formed by the first mechanism, but richer in In and Ga. In the final sample, obtained by prolonged heating at 230−270°C, all NCs were homogeneous in size and composition. Attempts to replace the native ligands on the surface of the NCs with sulfur ions (following literature procedures) resulted in only around 50% exchange. Films prepared using the partially ligand exchanged NCs exhibited good homogeneity and an ohmic dark conductivity and photoconductivity with a resistivity of about 50 Ω•cm.
Room-Temperature Synthesis of Hierarchical CuSCN Nanocrystals Using an Ionic Liquid Precursor
International Journal of Engineering Sciences & Research Technology, 2014
High-quality hierarchical CuSCN microcrystals assembled by nanoplates were successfully synthesized via a metathesis reaction between SCN- ions and CuCl in ionic liquid [Bmim]SCN. The as-obtained samples were characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that [Bmim]SCN played multiple roles during the formation process of hierarchical CuSCN microcrystals. This method is an effective and ecologically benign route to synthesize the hierarchical CuSCN microcrystals, without pollutant, heating and complicated equipment. This method is expected to be extended to synthesize other functional inorganic materials.
High-throughput route to Cu2―xS nanoparticles from single molecular precursor
2012
The copper(II) complex of 1,1,5,5-tetra-iso-propyl-2-thiobiuret was used as a single source precursor for the synthesis of copper sulfide nanoparticles in a continuous flow process. The nanoparticles had a spherical morphology and were produced either as a pure Cu 7 S 4 or Cu 7 S 4 with minor impurities of Cu 9 S 5 .