Room temperature evolution of gold nanodots deposited on silicon

Garozzo, C.; Filetti, A.; Bongiorno, Corrado; Magna, Antonino La; Simone, F.; Puglisi, Rosaria A.

doi:10.1007/s13404-014-0142-0

Cited by 7 publications

(11 citation statements)

References 24 publications

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“…The morphology of the samples was investigated with transmission electron microscopy (TEM). It has been reported in previous papers that the specimen preparation could alter the original and structural characteristics of the Au particles [ 25 ]. Therefore, we prepared the samples for TEM analysis using two different thinning procedures.…”

Section: Resultsmentioning

confidence: 99%

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

Milazzo¹,

Mio²,

D’Arrigo³

et al. 2017

Beilstein J. Nanotechnol.

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The morphology of gold nanoparticles (AuNPs) deposited on a (100) silicon wafer by simple immersion in a solution containing a metal salt and hydrofluoric acid (HF) is altered by HF treatment both before and after deposition. The gold clusters are characterized by the presence of flat regions and quasispherical particles consistent with the layer-by-layer or island growth modes, respectively. The cleaning procedure, including HF immersion prior to deposition, affects the predominantly occurring gold structures. Flat regions, which are of a few tens of nanometers long, are present after immersion for 10 s. The three-dimensional (3D) clusters are formed after a cleaning procedure of 4 min, which results in a large amount of spherical particles with a diameter of ≈15 nm and in a small percentage of residual square layers of a few nanometers in length. The samples were also treated with HF after the deposition and we found out a general thickening of flat regions, as revealed by TEM and AFM analysis. This result is in contrast to the coalescence observed in similar experiments performed with Ag. It is suggested that the HF dissolves the silicon oxide layer formed on top of the thin flat clusters and promotes the partial atomic rearrangement of the layered gold atoms, driven by a reduction of the surface energy. The X-ray diffraction investigation indicated changes in the crystalline orientation of the flat regions, which partially lose their initially heteroepitaxial relationship with the substrate. A postdeposition HF treatment for almost 70 s has nearly the same effect of long duration, high temperature annealing. The process presented herein could be beneficial to change the spectral response of nanoparticle arrays and to improve the conversion efficiency of hybrid photovoltaic devices.

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Section: Resultsmentioning

confidence: 99%

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

Milazzo¹,

Mio²,

D’Arrigo³

et al. 2017

Beilstein J. Nanotechnol.

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“…[32] but modified to obtain low and controlled etching rates. The first step is used to isotropically etch the Si, the second to deposit a passivation layer which covers and protects the lateral walls of the nanostructures for the successive etching steps [34]. The structural and morphological characterization of the nanopatterned samples has been performed by using a JEOL JEM TEM operating at 200 keV, equipped with a field emission gun and with an electron energy loss spectrometer in situ.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…To apply this process to our nanostructured samples it has been necessary to scale it down to obtain lower and controlled etching rates. The typical thickness to be etched is in the range of tens of nanometers, so to obtain controlled processes it has been necessary to achieve etching rates of about 100 nm min À1 , i.e., one order of magnitude lower than the typical Bosch processes [34]. Figure 4 reports the preliminary results of this investigation, i.e., the TEM images in cross view of two samples after the pattern transfer from the oxide hard mask down to the Si substrate which has been performed without breaking the vacuum between the two steps.…”

Section: Experimental Methodsmentioning

confidence: 99%

Nanofabrication processes for innovative nanohole-based solar cells

Garozzo

Bongiorno

Franco

et al. 2013

Phys. Status Solidi A

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The ability to form ordered nanostructures at the wafer level with low cost methodologies has represented a challenge in the last decade in many research fields spanning from nanoelectronics to photovoltaics (PVs). For the latter application the nanostructures have demonstrated interesting capabilities for exploiting the quantum effects in terms of efficient visible light absorption. To fabricate ordered nanostructures many solutions have been proposed but they provide feature densities lower than 10 9 cm À2 or present high fabrication costs. We propose a wafer level and low-cost Lithography based on block CoPolymers self-assembling (LCP), which allows the formation of nanofeatures controlled down to 10 nm and density higher than 5 Â 10 10 cm À2. We propose to use this technique to form radial junctions in nanoholes for solar cells. The approach is similar to that of the nanowires, i.e., it decouples the optical path of the visible photons from the electrical path of the carriers, but since the one-dimensional (1D) structures are embedded inside the bulk of the wafer the structure is more robust and allows easier implementation. To form the junction inside the nanoholes a novel strategy based on the deposition of monolayers of dopant-containing molecules is proposed. This technique allows to obtain shallow and controlled junction depths with peak carrier concentrations of about 10 19 cm À3 for both n-and p-type doping.

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“…The presence of the shell surrounding the Si-NWs was observed by several other research groups [39,40,41,42], but the reason behind its formation is not yet completely clear. A possible cause has been indicated in the weakness of the covalent bond of the silicon atoms at the interface with the gold that would remove them from the crystal lattice and let them spread through the gold dot toward its external surface, thus continuing to accumulate at the Au/air interface.…”

Section: Introductionmentioning

confidence: 93%

Study on the Physico-Chemical Properties of the Si Nanowires Surface

et al. 2019

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Silicon nanowires (Si-NWs) have been extensively studied for their numerous applications in nano-electronics. The most common method for their synthesis is the vapor–liquid–solid growth, using gold as catalyst. After the growth, the metal remains on the Si-NW tip, representing an important issue, because Au creates deep traps in the Si band gap that deteriorate the device performance. The methods proposed so far to remove Au offer low efficiency, strongly oxidize the Si-NW sidewalls, or produce structural damage. A physical and chemical characterization of the as-grown Si-NWs is presented. A thin shell covering the Au tip and acting as a barrier is found. The chemical composition of this layer is investigated through high resolution transmission electron microscopy (TEM) coupled with chemical analysis; its formation mechanism is discussed in terms of atomic interdiffusion phenomena, driven by the heating/cooling processes taking place inside the eutectic-Si-NW system. Based on the knowledge acquired, a new efficient etching procedure is developed. The characterization after the chemical etching is also performed to monitor the removal process and the Si-NWs morphological characteristics, demonstrating the efficiency of the proposed method and the absence of modifications in the nanostructure.

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Room temperature evolution of gold nanodots deposited on silicon

Cited by 7 publications

References 24 publications

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

Nanofabrication processes for innovative nanohole-based solar cells

Study on the Physico-Chemical Properties of the Si Nanowires Surface

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