Low temperature solvothermal synthesis of nanosized oxidic particles (original) (raw)
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Applied Physics A
electron transport properties and direct band gap structure, InN is a promising candidate for high-speed optoelectronic devices, broad-spectrum solar cells, high electron mobility transistors, near infrared light emitting diodes (LEDs) and high-speed laser diodes [2-4]. Furthermore, its nontoxic nature and infrared emission properties enable InN to be used in biological and medical applications [5]. Besides these advantageous properties of InN material, its nanostructures have been widely studied due to their different characteristics depending on the dimensionality and size, which allow the applications in nanoscale electronic and optoelectronic devices [6, 7]. InN crystallizes in two different structures: stable hexagonal (wurtzite) structure and metastable cubic structure. When compared to hexagonal InN, cubic InN possesses smaller band gap and superior electronic properties due to its isotropic lattice and lower phonon scattering [8]. However, the production of cubic InN-NCs is quite a challenging process due to its thermodynamically unstable nature [9]. Previous studies showed a number of techniques viable for the synthesis of InN-NCs mainly having hexagonal structure. Ambient pressure and low-temperature liquid phase was proposed as a suitable method for the synthesis of nanoparticles having low decomposition temperatures. It was shown that wurtzite InN-NCs having 6.2 nm average diameter are successfully produced using this method. These colloidal wurtzite InN-NCs were post-treated with nitric acid to get rid of the metallic indium byproduct and finally InN nano-powder was obtained [10]. Moreover, activated reactive evaporation and nitrogen plasma annealing methods were proposed for the successful production of wurtzite InN-NCs and InN nanorods, respectively. It was suggested that the technique is applicable to produce InN-NCs by using low temperatures from indium nanostructures obtained by different techniques [11]. Xiao et al.
A novel method for the synthesis of sub-microcrystalline wurtzite-type InxGa1−xN powders
Materials Science and Engineering: B, 2002
A novel method to synthesize wurtzite-type gallium-indium nitride powders (In x Ga 1 − x N, x= 0, 0.5, 1) with small particle size, high purity and high crystallinity has been developed. The method produces finely divided powders via the pyrolysis reaction of a complex salt (ammonium hexafluoroindium-gallate, (NH 4) 3 In x Ga 1 − x F 6) in an ultrahigh purity ammonia flow inside of a quartz tubular reactor at relatively low temperature, 630°C. The conditions of the process avoid the formation of metallic indium, oxides or fluorides. Scanning electron microscopy and X-ray diffraction analysis performed on these sub-micron particles of In x Ga 1 − x N show an hexagonal wurtzite-type structure, which is very similar to pure InN produced by the same technique.
The effective role of time in synthesising InN by chemical method at low temperature
Journal of Materials Science: Materials in Electronics, 2014
This study involves the synthesise of indium nitride (InN) nanoparticles at low temperature using a chemical method. Three samples were synthesised under different times to produce InN nanoparticle of high quality crystallinity. Results showed that the time of synthesise plays an important role for N enhancement in InN nanoparticle structure. The average diameters of cubic phase of InN nanoparticle were 16.5 nm. These properties support the use of InN as a potential material for the manufacture of highly efficient low cost solar cells.
Controlled synthesis of single-crystalline InN nanorods
Nanotechnology, 2007
Single-crystalline InN nanorods were successfully grown on c-Al 2 O 3 , GaN, Si(111), and Si(100) substrates by non-catalytic, template-free hydride metal-organic vapour phase epitaxy (H-MOVPE). It was evaluated thermodynamically and confirmed experimentally that the domain of nanorod growth lies in the vicinity of the growth-etch transition. Stable gas phase oligomer formation is suggested as the nucleation mechanism for InN nanoparticle generation. Dislocation-free, high-quality InN nanorods with [00.1] growth axis were formed via an apparent solid-vapour growth mechanism. The nanorod diameter, density, and orientation were controlled by growth temperature, substrate selection, and HCl/TMIn and N/In inlet molar ratios. S Supplementary data are available from stacks.iop.org/Nano/18/135606
Long-term oxidization and phase transition of InN nanotextures
Nanoscale Research Letters, 2011
The long-term (6 months) oxidization of hcp-InN (wurtzite, InN-w) nanostructures (crystalline/amorphous) synthesized on Si [100] substrates is analyzed. The densely packed layers of InN-w nanostructures (5-40 nm) are shown to be oxidized by atmospheric oxygen via the formation of an intermediate amorphous In-O x -N y (indium oxynitride) phase to a final bi-phase hcp-InN/bcc-In 2 O 3 nanotexture. High-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy and selected area electron diffraction are used to identify amorphous In-O x -N y oxynitride phase. When the oxidized area exceeds the critical size of 5 nm, the amorphous In-O x -N y phase eventually undergoes phase transition via a slow chemical reaction of atomic oxygen with the indium atoms, forming a single bcc In 2 O 3 phase.
Synthesis and characterization of In2O3nanoparticles
Journal of the Korean Physical Society, 2014
Metal-oxide nanostructures have elicited increasing interest in both fundamental and applied sciences. Among metal oxide nanostructures, In2O3 has the potential for use asa semiconductor material. This article provides details on studies carried out thus far for the synthesis and the characterization of In2O3 nanostructures. In this research, various techniques were investigated for the fabrication of diverse and fascinating spherical shaped In2O3 nanostructures. Brunauer-Emmett-Teller (BET) analyses of the In2O3 nanostructures through detailed refinements of the structure of the In2O3 nanoparticles by using the Rietveld method, followed by microstructural analyses using scanning electron microscopy/ transmission electron microscopy (SEM/TEM) and a chemical composition analysis are presented and discussed. Decreasing crystallinity with an improvement in specific surface area was observed from the structural characterization. The energy dispersive analysisresults showed that the as-prepared In2O3 powder sample was stoichiometric, containing almost equal proportions of indium and oxygen. The microstructural analysis (TEM and SEM) demonstrated precise control over the diameters of the nanoparticles, which is an important advantage of the solution combustion approach.
A kinetic study of indium nitride formation from indium oxide powders
Materials Science and Engineering: B, 2002
Indium oxide powders were reacted in flowing ammonia at various temperatures and times to form indium nitride (InN), and the kinetics of the oxide-to-nitride reaction was quantitatively determined by X-ray diffraction analysis. The quantity of the InN phase formed increased expectedly at higher temperatures and longer times showing a stretched-out exponential dependence. The reaction rate constant at a given temperature was determined using the Avrami equation. The activation energy for the reaction was calculated to be 164.5 KJ mol (1 in the temperature range of 580 Á/650 8C and the Avrami constant varied between 1.56 and 2.8.
Nanoscale Research Letters, 2009
Indium oxide (In2O3) nanocrystals (NCs) have been obtained via atmospheric pressure, chemical vapour deposition (APCVD) on Si(111) via the direct oxidation of In with Ar:10% O2 at 1000 °C but also at temperatures as low as 500 °C by the sublimation of ammonium chloride (NH4Cl) which is incorporated into the In under a gas flow of nitrogen (N2). Similarly InN NCs have also been obtained using sublimation of NH4Cl in a gas flow of NH3. During oxidation of In under a flow of O2 the transfer of In into the gas stream is inhibited by the formation of In2O3 around the In powder which breaks up only at high temperatures, i.e. T > 900 °C, thereby releasing In into the gas stream which can then react with O2 leading to a high yield formation of isolated 500 nm In2O3 octahedrons but also chains of these nanostructures. No such NCs were obtained by direct oxidation for T G 4Cl in the In leads to the sublimation of NH4Cl into NH3 and HCl at around 338 °C which in turn produces an efficient dispersion and transfer of the whole In into the gas stream of N2 where it reacts with HCl forming primarily InCl. The latter adsorbs onto the Si(111) where it reacts with H2O and O2 leading to the formation of In2O3 nanopyramids on Si(111). The rest of the InCl is carried downstream, where it solidifies at lower temperatures, and rapidly breaks down into metallic In upon exposure to H2O in the air. Upon carrying out the reaction of In with NH4Cl at 600 °C under NH3 as opposed to N2, we obtain InN nanoparticles on Si(111) with an average diameter of 300 nm.
UV-assisted synthesis of indium nitride nano and microstructures
J. Mater. Chem. A, 2015
Indium nitride (InN) has been made the first time by a combined thermal/UV photo-assisted process. Indium oxide (In 2 O 3 ) was reacted with ammonia using two different procedures in which either the ammonia was photolysed or both In 2 O 3 and ammonia were photolysed. A wide range of InN structures were made by these procedures that were determined by the reaction conditions (time, temperature). The reaction of In 2 O 3 with photolysed NH 3 gave InN rod-like structures that were made of stacked cones (6 h/750 C) or discs (6 h/800 C) and that contained some In 2 O 3 residue. In contrast, photolysis of both In 2 O 3 and NH 3 gave InN nanowires and pure InN nanotubes filled with In metal (>90%). The transformation of the 3D In 2 O 3 particles to the tubular 1D InN was monitored as a function of time (1-4 h) and temperature (700-800 C); the product formed was very sensitive to temperature. The band gap of the In filled InN nanotubes was found to be 1.89 eV. † Electronic supplementary information (ESI) available: XRD patterns of InN materials with oxide impurities synthesised from a reaction of In 2 O 3 with photolysed NH 3 at different temperatures for a period of 6 h. See
Liquid Phase Synthesis of indium tin oxide (ITO) nanoparticles using In(III) and Sn(IV) salts
Indium tin oxide (ITO) nanoparticles are prepared by two hydrothermal and liquid-phase co-precipitation methods under given conditions with solution of indium chloride (InCl3·4H2O), tin chloride (SnCl4·5H2O) in ethylenedyamine solution. The samples were characterized by XRD and SEM analysis after heat treatments. The SEM results showed that, the size of ITO particles prepared by ethylendiamide co-precipitation are increased from 35 nm to 120 nm. The XRD results revealed that the size and crystallity of the ITO particles is increased by hydrothermal method. The XRD results indicated that the intensity ratio of I400/I222 has a decrease of 21.67% by hydrothermal method.