Propagation of amorphous oxide nanowires via the VLS mechanism: growth kinetics

Abstract

This work reports the growth kinetics of amorphous nanowires (NWs) developed by the vapour-liquidsolid (VLS) mechanism. The model presented here incorporates all atomistic processes contributing to the growth of amorphous oxide NWs having diameters in the 5-100 nm range. The steady state growth condition has been described by balancing the key atomistic process steps. It is found that the 2D nanocatalyst liquid and NW solid (L-S) interface plays a central role in the kinetic analysis. The balance between the 2D Si layer crystallization and oxidation rate is quantitatively examined and compared with experimental values. The atomistic process dependencies of the NW growth rate, supersaturation (C/C 0 ), desolvation energy (Q D ) barrier and NW diameter have been analyzed in detail. The model successfully predicts the reported NW growth rate to be in the range of 1-10 mm s À1 . A novel seed/catalyst metalbased synthesis strategy for the preparation of amorphous silica NWs is reported. A nickel thin film on Si is used as a seed metal for the Au assisted VLS growth of silica NWs. The experimental results provide evidence of the creation of SiO under the given conditions followed by Si injection in the Au-Si nanocatalyst solution. The usage of seed metal was observed to reduce the growth temperature compared to the methods reported in the literature and obtain similar growth rates. The technique presented here holds promise for the synthesis of sub-100 nm diameter NWs.

Protocol for growing silica nanowires on various substrates to enhance superwetting and self-jumping properties

“…For the silicon wafer, the deposition time is 10 s while that of metal foils is 30 s. To evaluate the thickness of the Pt film, we first deposit a correction fluid as a mask before Pt deposition and then remove it by ultrasonic acetone cleaning to create a step for tip scanning in atomic force microscopy (AFM). Compared to a previous study in which the film may break into droplets ( Shakthivel et al., 2019 ), this method allows the creation of a step down to less than 2 nm ( Lee et al., 2019 ). Pt has a fine grain size relative to Au, which is beneficial for thinner coatings.…”

Connected Sensors, Innovative Sensor Deployment, and Intelligent Data Analysis for Online Water Quality Monitoring

“…For example, nanostructured materials exhibit high surface to volume ratio, and hence the fast response and high sensitivity [20,[78][79][80]. In addition, the shape or morphology of the nanomaterial could influence the sensor performance [81,82]. The porosity, pore size and grain size of the crystals influence on the response time.…”

High-performance printed electronics based on inorganic semiconducting nano to chip scale structures

“…The inorganic materials-based nano to macro scale structures (sub-100 nm to wafer scale) discussed above could be fabricated using either bottom-up or top down approaches through wide variety of physical and chemical techniques, as summarised in Fig. 3 [70,[74][75][76][77][78]. The developed techniques largely aim to produce structures with precisely controlled dimensions and chemical composition which are crucial for the development of novel flexible devices (e.g.…”

“…The major advantage of the bottom-up approaches is their ability to precisely tune crystallinity and composition during the growth process. Synthesis strategies, including catalyst particle assisted vapour-liquid-solid (VLS) [75,[110][111][112], vapour-solid (VS) [113][114][115][116], vapour-solid-solid (VSS) [117][118][119][120][121], and low-temperature solution-based processes such as hydrothermal [74,79,83] have been widely exploited for growing inorganic NWs. The VLS growth of NWs (Fig.…”