Solution-liquid-solid growth

Trentler T J ef a/1997 Solution-liquid-solid growth of indium phosphide fibers from organometallic precursors elucidation of molecular and non-molecular components of the pathway J. Am. Chem. Soc. 119 2172... 

Trentler T J ef a/1995 Solution-liquid-solid growth of orystalline lll-V semioonduotors an analogy to vapor-liquid-solid growth Science 270 1791... 

Trentler, T. J. Hickman, K. M. Goel, S. C. Viano, A. M. Gibbons, P. C. Buhro, W. M. 1995. Solution-liquid-solid growth of crystalling III-V semiconductors—an analogy to vapor-liquid-solid growth. Science 270 1791-1794. 

Buhro W E, Hickman K M and Trentler T J 1996 Turning down the heat on semiconductor growth—solution chemical syntheses and the solution-liquid-solid mechanism Adv. Mater. 8 685... 

The most important nanomaterial synthesis methods include nanolithography techniques, template-directed syntheses, vapor-phase methods, vapor-liquid-solid (VLS) methods, solution-liquid-solid (SLS) approaches, sol-gel processes, micelle, vapor deposition, solvothermal methods, and pyrolysis methods [1, 2]. For many of these procedures, the control of size and shape, the flexibility in the materials that can be synthesized, and the potential for scaling up, are the main limitations. In general, the understanding of the growth mechanism of any as-... 

Solution-Liquid-Solid (SLS) growth of semiconductor nanowires by Wang etal. (2006). The synthesis proceeds by a solution-based catalysed growth mechanism in which nanometer-scale metallic droplets catalyse the decomposition of metallo-organic precursors and crystalline nanowire growth. 

Most of the aforementioned methods use gas-phase feedstock, including CVD via the VLS mechanism in the presence of metal catalysts, evaporation at high temperatures without the use of metal catalysts, or laser vaporization in the presence of metal catalysts. Solution-liquid-solid methods have been explored in the presence of metal catalysts and under supercritical conditions. These two mechanisms can result in either tip or root growth, meaning that the catalysts can be either suspended in space at the tips of the growing nanowires, or anchored at the surface of the substrate, depending on the strength of interactions between the nanoparticles and the substrate. 

Fundamental aspects of vapor-liquid-solid (VLS) semiconductor nanowire growth are presented here. The synthesis of VLS semiconductor has been extended to different reaction media and pathways from the early chemical vapor deposition (CVD) approach, including solution-liquid-solid (SLS) and supercritical fluid-liquid-solid (SFLS), laser-catalyzed growth, and vapor-liquid-solid-epitaxy. The properties of nanowires grown by these VLS embodiments are compared. In this entry, VLS growth of nanowire heterostructures and oriented and hyperbranched arrays is examined. In addition, surface passivation and functionalization are assessed, and the importance of these techniques in the progress toward VLS produced nanowire devices is detailed. 

Organometallic precursors were also used for the preparation of III-V semiconductors. Buhro reported the use of a single-source precursor Bu 2ln[/t-P(SiMe3)2] 2, which upon methanolysis in toluene leads to a mixture of InP and In nanoparticles, which promote the growth of InP fibers through a solution-liquid-solid mechanism. " ... 

Amorphous and polycrystalline fibers and near-single crystal whiskers were obtained having diameters of 10-150 nanometers and lengths of several micrometers. Growth of whiskers and short fibers by this method is believed to proceed by a solution-liquid-solid (SLS) phase transformation, suggesting that similar synthesis routes may now also become available for other covalent short fibers and perhaps whiskers. 

Figure 6.82. Schematic illustrations of (a) VLS, (b) SLS solution-liquid-solid, and (c) SLS solid-liquid-solid 1-D nanostmctural growth.

Describe die Vapor-Liquid-Sofid, Solution-Liquid-Solid, and Sofid-Liquid-Sofid syndietic routes fOT 1-D nanostructural growth. Make sure you discuss the experimental setup and required precursor(s) for each technique, as well as the morphological control (i.e., control over thickness, length, chirality, etc.) one would have for each technique. 

Petchsang et al. reported the growth of ZnSe and ZnSe/CdSe eore/shell NWs by the solution-liquid-solid (SLS) growth method. ZnSe NWs of 15 to 28 nm diameter were synthesised by instant injection of a mixture of trioctylphosphine selenide (TOPSe), trioctylphosphine (TOP) and Bids to zinc stearate in trioetylphosphine oxide (TOPO) at 310 °C. Bismuth nano-partieles produeed from Bids catalysed the growth of ZnSe NWs as suggested by the SLS meehanism and were found attached at the tips of the nanowires (Fig. la). XRD analysis indieated the presence of both zinc... 

Hydrothermal-growth is usually defined as the use of an aqueous solvent at elevated temperature and pressure to dissolve a solute which would be insoluble under ordinary conditions. The advantages of the hydrothermal technique are a low growth temperature, a AT close to 0 at liquid/solid interface, an easily scalable technique, the reduction of most of the impurities from source. The disadvantages are the presence of intermediate products, the lithium or sodium or potassium incorporation when such solvents as LiOH, NaOH or KOH are used, the slow growth rates ( 10 mils per day), the inert liner needed, the occasional incorporation of OH and H2O. 

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