Free carrier enhanced depletion in ZnO nanorods decorated with bimetallic AuPt nanoclusters

Bahariqushchi, Rahim; Cosentino, Salvatore; Scuderi, M.; Dumons, E.; Tran-Huu-Hue, Louis-Pascal; Strano, Vincenzina; Grandjean, D.; Lievens, Peter; Poulin‐Vittrant, Guylaine; Spinella, C.; Terrasi, A.; Franzò, G.; Mirabella, S.

doi:10.1039/d0nr04134c

Cited by 17 publications

(21 citation statements)

References 62 publications

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“…RBS analyses ( Figure 1 f) confirmed the presence of a small amount of Au (peak at 1.8 MeV) and Zn (large peak at 1.0–1.5 MeV) onto Si (signal from 0.6 MeV downward), as expected. RBS was used to perform a quantitative measurement of Au after multiple immersion, since the Au amount is proportional to the Au peak in the spectrum [ 19 ]. Figure 1 g shows the variation in Au amounts with the number of immersions, showing a fairly linear increase from

(after 1 immersion) to

(after 20 immersions).…”

Section: Resultsmentioning

confidence: 99%

“…The surface decoration of semiconductor nanostructures with metallic nanoparticles (NPs) usually leads to an improvement of their catalytic and electrical properties [ 10 , 11 , 12 , 13 , 14 ]. The formation of nano-Schottky junctions at the metal–semiconductor interface leads to the creation of a strong electric field directed toward the surface and to a significant modification of the ZnO NRs energy band profiles [ 15 , 16 , 17 , 18 , 19 ]. As a consequence, space charge regions and surface-localized electric fields promote a catalytic effect and modify the radiative recombination process.…”

Section: Introductionmentioning

confidence: 99%

“…Apart from near-band-edge emission, ZnO nanostructures may also exhibit luminescence in the visible range [ 1 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. When decorated, luminescence from ZnO NRs changes, with an enhancement of visible emission at the expense of UV emission [ 10 , 19 , 28 , 29 ]. Such a process could be the consequence of a significant bending of electronic energy bands into ZnO just below the metal nanoparticle, inducing free carrier depletion.…”

Section: Introductionmentioning

confidence: 99%

“…Such a process could be the consequence of a significant bending of electronic energy bands into ZnO just below the metal nanoparticle, inducing free carrier depletion. Such an effect in decorated ZnO nanorods allows the application of these composite materials in UV sensing and light-induced catalysis [ 11 , 16 , 18 , 19 , 30 , 31 ].…”

Section: Introductionmentioning

confidence: 99%

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Localized Energy Band Bending in ZnO Nanorods Decorated with Au Nanoparticles

et al. 2021

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Surface decoration by means of metal nanostructures is an effective way to locally modify the electronic properties of materials. The decoration of ZnO nanorods by means of Au nanoparticles was experimentally investigated and modelled in terms of energy band bending. ZnO nanorods were synthesized by chemical bath deposition. Decoration with Au nanoparticles was achieved by immersion in a colloidal solution obtained through the modified Turkevich method. The surface of ZnO nanorods was quantitatively investigated by Scanning Electron Microscopy, Transmission Electron Microscopy and Rutherford Backscattering Spectrometry. The Photoluminescence and Cathodoluminescence of bare and decorated ZnO nanorods were investigated, as well as the band bending through Mott–Schottky electrochemical analyses. Decoration with Au nanoparticles induced a 10 times reduction in free electrons below the surface of ZnO, together with a decrease in UV luminescence and an increase in visible-UV intensity ratio. The effect of decoration was modelled with a nano-Schottky junction at ZnO surface below the Au nanoparticle with a Multiphysics approach. An extensive electric field with a specific halo effect formed beneath the metal–semiconductor interface. ZnO nanorod decoration with Au nanoparticles was shown to be a versatile method to tailor the electronic properties at the semiconductor surface.

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(after 1 immersion) to

(after 20 immersions).…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Localized Energy Band Bending in ZnO Nanorods Decorated with Au Nanoparticles

et al. 2021

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“…Au electroless deposition (ELD) [16] represents an attractive solution-based method for decorating nanostructures, allowing low cost and versatility for depositing films or nanoparticles [17][18][19][20][21][22][23][24]. A reliable method for Au cluster decoration could be used in several applications such as DNA sensing [25], UV sensing [26], and gas sensing [27].…”

Section: Introductionmentioning

confidence: 99%

Role of Substrate in Au Nanoparticle Decoration by Electroless Deposition

et al. 2020

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Decoration of nanostructures is a promising way of improving performances of nanomaterials. In particular, decoration with Au nanoparticles is considerably efficient in sensing and catalysis applications. Here, the mechanism of decoration with Au nanoparticles by means of low-cost electroless deposition (ELD) is investigated on different substrates, demonstrating largely different outcomes. ELD solution with Au potassium cyanide and sodium hypophosphite, at constant temperature (80 °C) and pH (7.5), is used to decorate by immersion metal (Ni) or semiconductor (Si, NiO) substrates, as well as NiO nanowalls. All substrates were pre-treated with a hydrazine hydrate bath. Scanning electron microscopy and Rutherford backscattering spectrometry were used to quantitatively analyze the amount, shape and size of deposited Au. Au nanoparticle decoration by ELD is greatly affected by the substrates, leading to a fast film deposition onto metallic substrate, or to a slow cluster (50–200 nm sized) formation on semiconducting substrate. Size and density of resulting Au clusters strongly depend on substrate material and morphology. Au ELD is shown to proceed through a galvanic displacement on Ni substrate, and it can be modeled with a local cell mechanism widely affected by the substrate conductivity at surface. These data are presented and discussed, allowing for cheap and reproducible Au nanoparticle decoration on several substrates.

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