Indium Nanoparticles Research Articles

Tracking the restructuring of oxidized silver-indium nanoparticles under a reducing atmosphere by environmental HRTEM.

Multimetallic nano-alloys display a structure and consequently physicochemical properties evolving in a reactive environment. Following and understanding this evolution is therefore crucial for future applications in gas sensing and heterogeneous catalysis. In view hereof, the structural evolution of oxidized Ag25In75 bimetallic nanoparticles under varying H2 partial pressures (PH2) and substrate temperatures (Ts) has been investigated in real-time through environmental transmission microscopy (E-TEM) while maintaining the atomic resolution. Small Ag25In75 bimetallic nanoparticles, produced by laser vaporization, are found (after air transfer) to contain an indium-oxide shell surrounding a silver-rich alloyed phase. For high PH2 and Ts, the direct reduction of the indium oxide shell, immediately followed by the melting or the diffusion onto the carbon substrate of the reduced indium atoms, is found to be the dominant mechanism. This reduction is concomitant with the growth of the core, indicating a partial diffusion of indium atoms from the shell towards the particle volume. The "surviving" particles therefore consist of a silver-indium alloy, very stable and remarkably resistant against oxidation contrary to native clusters. Interestingly, in the (PH2, Ts) space, the transition from "soft" (core-shell particles for low (PH2, Ts) values) to "strong" reduction conditions (silver-rich alloys for high (PH2, Ts) products) defines an intermediate domain where the preferred formation of Janus structures is detected. These results are discussed in terms of thermodynamic driving forces in relation to alloying and interface energies. This work shows the potential of high-resolution ETEM for unravelling the mechanisms of nanoparticle reorganization in a chemically reactive environment.

Synthesis of indium nanoparticles at ambient temperature; simultaneous phase transfer and ripening.

The synthesis of size-monodispersed indium nanoparticles via an innovative simultaneous phase transfer and ripening method is reported. The formation of nanoparticles occurs in a one-step process instead of well-known two-step phase transfer approaches. The synthesis involves the reduction of InCl3 with LiBH4 at ambient temperature and although the reduction occurs at room temperature, fine indium nanoparticles, with a mean diameter of 6.4 ± 0.4 nm, were obtained directly in non-polar n-dodecane. The direct synthesis of indium nanoparticles in n-dodecane facilitates their fast formation and enhances their size-monodispersity. In addition, the nanoparticles were highly stable for more than 2 months. The nanoparticles were characterised by dynamic light scattering (DLS), small angle X-ray scattering (SAXS), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy to determine their morphology, structure and phase purity.

Optical and Electrical Performance of MOS-Structure Silicon Solar Cells with Antireflective Transparent ITO and Plasmonic Indium Nanoparticles under Applied Bias Voltage.

This paper reports impressive improvements in the optical and electrical performance of metal-oxide-semiconductor (MOS)-structure silicon solar cells through the incorporation of plasmonic indium nanoparticles (In-NPs) and an indium-tin-oxide (ITO) electrode with periodic holes (perforations) under applied bias voltage. Samples were prepared using a plain ITO electrode or perforated ITO electrode with and without In-NPs. The samples were characterized according to optical reflectance, dark current voltage, induced capacitance voltage, external quantum efficiency, and photovoltaic current voltage. Our results indicate that induced capacitance voltage and photovoltaic current voltage both depend on bias voltage, regardless of the type of ITO electrode. Under a bias voltage of 4.0 V, MOS cells with perforated ITO and plain ITO, respectively, presented conversion efficiencies of 17.53% and 15.80%. Under a bias voltage of 4.0 V, the inclusion of In-NPs increased the efficiency of cells with perforated ITO and plain ITO to 17.80% and 16.87%, respectively.

Ordered mesoporous In-(TiO2/WO3) nanohybrid: An ultrasensitive n-butanol sensor

Indium doped 2-D mesoporous (TiO2/WO3) nanohybrids possessing large intrinsic surface area and ordered pore channels were synthesized using mesoporous silica, SBA-15 as hard template through a simple nanocasting strategy. The TiO2/WO3 was synthesized as a result of negative replica of SBA-15 template during nanocasting process, which was further modified with Indium nanoparticles using wet impregnation technique. The nanohybrids were tested against the detection of important indoor flammable organic pollutants including n-butanol, toluene, benzene, xylene, 2-propanol and ethyl acetate. The sensing results illustrate that 1wt% In-doped in TiO2/WO3 shows 2.65 times better response (R=127.2 @ 200°C) to 50ppm n-butanol gas than pure TiO2/WO3 (R=48 @ 210°C) nanocomposite at relatively lower operating temperature. A fast response time (2.2s), rapid recovery time (3s), linear response, high stability and excellent selectivity were observed for the developed nanohybrid sensor. It is expected that the promising findings reported in this study can be extended to synthesize ordered mesoporous nanostructures which will be useful for the design and construction of futuristic e-nose with enhanced gas-sensing performance.

Electrical and optical performance of plasmonic silicon solar cells based on light scattering of silver and indium nanoparticles in matrix-combination.

This study demonstrates the efficacy of combining a matrix of silver nanoparticles (Ag-NPs) with indium nanoparticles (In-NPs) to improve the electric and optical performance of plasmonic silicon solar cells. We examined the excitation of localized surface plasmons of Ag-NPs and In-NPs using surface enhanced Raman scattering measurements. Optical reflectance and external quantum efficiency (EQE) measurements demonstrate that the light scattering of Ag-NPs at short wavelengths can be improved by surrounding them with In-NPs. This also leads to high EQE band matching in the high energy band of the AM1.5G solar energy spectrum. Impressive improvements in optical reflectance and EQE response were also observed at short wavelengths. Cells with a matrix of Ag-NPs (20% surface coverage) surrounded by In-NPs (80% surface coverage) increased the overall efficiency of the cell by 31.83%, as confirmed by photovoltaic current density-voltage characterization under AM 1.5 G illumination.

External quantum efficiency and photovoltaic performance of silicon cells deposited with aluminum, indium, and silver nanoparticles

In this study, the plasmonic light scattering of aluminum (Al), indium (In), and sliver (Ag) nanoparticles (NPs) deposited on silicon solar cells was demonstrated. For comparison, the dimensions of all NPs were maintained at 17–25 nm with a coverage of approximately 30–40% through the control of film deposition and thermal annealing conditions. Absorbance and surface plasmon Raman scattering were used to examine the different localized surface plasmon resonances (LSPRs) of the proposed NPs. Optical reflectance, external quantum efficiency (EQE) response, and photovoltaic current density–voltage characteristics under AM 1.5G illumination were used to confirm the contribution of the plasmonic light scattering of the NPs. The conversion efficiencies of the solar cells with Al, In, and Ag NPs increased 1.21-, 1.23-, and 1.17-fold, respectively, compared with that of the reference bare Si solar cell. The EQE response and photovoltaic performance revealed that Al and In NPs produced broadband plasmonic light scattering and increased efficiency, far exceeding the results obtained using Ag NPs.

Plasmonics modulation of Si solar cell with a matrix silver nanoparticles pattern surrounded by indium nanoparticles

This paper demonstrates the fabrication of plasmonic silicon (Si) solar cells with a matrix comprising a pattern of silver nanoparticles (Ag-NPs) surrounded by indium nanoparticles (In-NPs). We examined the plasmonic-modulated light scattering induced by Ag-NPs/In-NPs matrices with various degrees of coverage using optical as well as electrical measurements. The Raman scattering of In-NPs and Ag-NPs was characterized using a semiconductor laser at a wavelength of 532nm and output power of 0.36W. We also measured the optical reflectance and external quantum efficiency response of various solar cells. We achieved impressive results with regard to plasmonic-modulated light scattering through the implementation of a matrix that included Ag-NP coverage of 20% and In-NP coverage of 80% over an area of 4×4mm2. This resulted in a 9.93% increase in short-circuit current density (from 31.91mA/cm2 to 35.08mA/cm2) and a 10.12% increase in conversion efficiency (from 13.04% to 14.36%), compared to cells with uniformly distributed Ag-NPs.

Production of In, Au, and Pt nanoparticles by discharge plasmas in water for assessment of their bio-compatibility and toxicity

ABSTRACTNanoparticles have great potential for biomedical applications such as early detection, accurate diagnosis, and personalized treatment of cancer. Assessment of bio-compatibility and toxicity of nanoparticles body is an emerging topic for these applications. To study kinetics of nanoparticles in body, we synthesized indium, gold and platinum nanoparticles in aqueous suspension using pulsed electrical discharge plasmas in water. The average size of synthesized primary nanoparticles for indium, gold, and platinum are 6.2 nm, 6.7 nm, and 5.4 nm, whereas the average size of secondary nanoparticles for indium, gold, and platinum are 315 nm, 72.3 nm, and 151 nm, respectively. Synthesized indium nanoparticles are transported from subcutaneous to serum and brain. The indium content in serum for the synthesized nanoparticles is much higher than that for the In2O3 nanoparticles of 150 nm in primary size. For gold and platinum nanoparticles, preliminary examination of intratracheal administration revealed that administration of synthesized nanoparticles with 10 mg/kg BW (body weight) may cause bleedings and/or emphysema in lung.

Mild bottom-up synthesis of indium(0) nanoparticles: characterization and application in the allylation of carbonyl compounds

A mild bottom-up synthesis of indium(0) nanoparticles (4.0 ± 0.5 nm) was developed and efficiently applied in the allylation of carbonyl compounds.

The role of water in the synthesis of indium nanoparticles.

We report the water-assisted synthesis of indium nanoparticles (In NPs). We found that a precise amount of water was necessary to allow the formation of the desired 7 nm In NPs: the oxidation of the In surface by water inhibits the growth of NPs as well as subsequent reactivity with white phosphorus (P4). A novel surface activation method based on the use of organosilanes is presented.

Enhanced Carbon Dioxide Reduction Activity on Indium-Based Nanoparticles

Nanoparticles of indium, indium hydroxide, and indium oxide were synthesized and evaluated for their electrocatalytic abilities in the reduction of CO2 to formate. These nanoparticles were characterized with several microscopic and spectroscopic techniques in order to investigate their structure and surface features. Their electrochemical behavior was also probed through voltammetry and bulk electrolysis. faradaic efficiencies approaching 100% were achieved on these particles at potentials as positive as −1.3 V vs. Ag/AgCl, which represents a significant decrease in the overpotential compared to that observed using bulk indium electrodes. The nanostructuring of the particles and the partial surface oxidation of the indium nanoparticles to yield catalytic surface indium hydroxide species are implicated in the high efficiencies at low overpotentials.

Plasmonic Indium Nanoparticle‐Induced High‐Performance Photoswitch for Blue Light Detection

Plasmonic nanostructures composed of poor metals (e.g., In, Cu, Al) have lately received increasing interest due to their low cost and natural abundance relative to noble metal nanoparticles (e.g., Au, Ag, Pt). To date, while considerable progress has been achieved with regard to the utilization of plasmonic noble metal nanostructures for optimizing various optoelectronic devices, little work has been performed to study the device appplication of poor metals. In this study, a high‐performance blue light nano‐photodetector is induced through the use of a highly ordered indium nanoparticle (InNP) array. Electrical analysis reveals that, after decoration with the plasmonic InNP array, the photocurrent of the nano‐photodetector increases considerably, giving rise to an obvious increase in responsivity and gain. Such an increase in device performance, according to simulations based on the finite element method, is attributed to the plasmonic InNPs which can induce direct electron transfer from InNPs to ZnSe nanoribbons. This study suggests that poor metal nanoparticles are equally important candidates for boosting the device performance of light‐harvesting optoelectronic devices.

Performance-Enhanced Textured Silicon Solar Cells Based on Plasmonic Light Scattering Using Silver and Indium Nanoparticles.

Performances of textured crystalline-silicon (c-Si) solar cells enhanced by silver nanoparticles (Ag-NPs) and indium nanoparticles (In-NPs) plasmonic effects are experimentally demonstrated and compared. Plasmonic nanoparticles integrated into textured c-Si solar cells can further increase the absorption and enhance the short-circuit current density (Jsc) of the solar cell. To examine the profile of the proposed metallic particles, the average diameter and coverage of the In-NPs (Ag-NPs) at 17.7 nm (19.07 nm) and 30.5% (35.1%), respectively, were obtained using scanning electron microscopy. Optical reflectance and external quantum efficiency response were used to measure plasmonic light scattering at various wavelengths. Compared to a bare reference cell, the application of In-NPs increased the Jsc of the cells by 8.64% (from 30.32 to 32.94 mA/cm2), whereas the application of Ag-NPs led to an increase of 4.71% (from 30.32 to 31.75 mA/cm2). The conversion efficiency of cells with embedded In-NPs (14.85%) exceeded that of cells with embedded Ag-NPs (14.32%), which can be attributed to the broadband plasmonic light scattering of the In-NPs.

Bridging the Gap between the Nanometer-Scale Bottom-Up and Micrometer-Scale Top-Down Approaches for Site-Defined InP/InAs Nanowires.

This work presents a method that bridges the gap between the nanometer-scale bottom-up and micrometer-scale top-down approaches for site-defined nanostructures, which has long been a significant challenge for applications that require low-cost and high-throughput manufacturing processes. We realized the bridging by controlling the seed indium nanoparticle position through a self-assembly process. Site-defined InP nanowires were then grown from the indium-nanoparticle array in the vapor-liquid-solid mode through a "seed and grow" process. The nanometer-scale indium particles do not always occupy the same locations within the micrometer-scale open window of an InP exposed substrate due to the scale difference. We developed a technique for aligning the nanometer-scale indium particles on the same side of the micrometer-scale window by structuring the surface of a misoriented InP (111)B substrate. Finally, we demonstrated that the developed method can be used to grow a uniform InP/InAs axial-heterostructure nanowire array. The ability to form a heterostructure nanowire array with this method makes it possible to tune the emission wavelength over a wide range by employing the quantum confinement effect and thus expand the application of this technology to optoelectronic devices. Successfully pairing a controllable bottom-up growth technique with a top-down substrate preparation technique greatly improves the potential for the mass-production and widespread adoption of this technology.

The effect of Indium metal nanoparticles on the electronic properties of organic light emitting diodes (OLEDs)

In this paper the effect of Indium nanoparticles (NPs) on the electronic properties of organic light emitting diodes (OLEDs) is experimentally investigated. The metal NPs which are added to the hole transfer layer can be considered as a blocker layer for injected electrons. By optimizing hole and electron ratio, current density and voltage can be decreased. In order to study this effect, among various fabricated devices, a specific structure, namely ITO/PEDOT:PSS (50nm)/TPD (45nm)/NPs (xnm)/Alq3 (50nm)/Ag (80nm) has been used. Also, the experiment is investigated for Au and Cu as different cathode the results of structures are compared with Ag cathode. A manually controllable shutter was used for vacuum deposition process to prepare the same structures and to avoid any disturbing effects. It is observed that specific Indium NPs reduce current density and turn on voltage of the device.

Performance enhancement of plasmonics silicon solar cells using Al2O3/In NPs/TiO2 antireflective surface coating

In this study, the enhancement of silicon solar cell photovoltaic performance by means of indium nanoparticles (In NPs) deposited on the TiO2 space layer and capped with an Al2O3 antireflective layer is demonstrated. The impressive performance enhancement is attributed to the plasmonic scattering of broadband light which occurs as a result of the Al2O3/In NPs/TiO2 antireflective coating (PARC) surface structure. The optical reflectance, photovoltaic current-voltage (I–V), external quantum efficiency (EQE), and photovoltaic performance as a function of the incident angles are measured and compared. The experimental results show that the reflectance decreases with increasing TiO2 thickness and that the lowest reflection point of the spectrum was red-shifted by the use of a PARC surface structure. EQE was significantly enhanced between 400 and 1050nm wavelengths and much high EQE of 85% were observed for the cell with In NPs embedded in the 65-nm Al2O3/20nm TiO2 layer structure. In comparison to a bare reference solar cell, an efficiency enhancement of 54.47% (from 10.96% to 16.93%) and a short-circuit current density enhancement of 52.83% (from 26.10 to 39.89mA/cm2) were obtained for the cell with a 65-nm Al2O3/In NPs/20-nm TiO2 antireflection structure under normal incident illumination. In addition, for incident angles from 0° to 15°, the 0.78% decrease in conversion efficiency (from 16.71% to 16.58%) of the cell with the PARC surface structure was less than the 3.28% (from 13.86% to 13.49%) decrease of the cell with 65-nm Al2O3/20-nm TiO2 double layer antireflective coating (DL-ARC) due to the plasmonic scattering of broadband light.

Synthesis, characterization and optical properties of ligand-protected indium nanoparticles.

Unlike silver and gold, indium has material properties that enable strong resonances extended up to the ultraviolet. This extended response, combined with low cost, and ease of synthesis process, makes indium a highly promising material for applications. In this work, we have synthesized ligand-protected indium nanoparticles by a metal reduction method. Powder X-ray diffraction and EDX analyses are consistent with the presence of metallic indium in the nanoparticles. Ligand binding was proven by IR spectroscopy and TGA experiments. TEM analyses reveal that the particle size ranges from 6.3 to 4.8 nm. Optical measurements show that the absorption maximum is red shifted as the particle size decreases.

Mechanism for laser-induced fluorescence signal generation in a nanoparticle-seeded flow for planar flame thermometry

The mechanism of atomic indium generation for laser-induced fluorescence (LIF) of indium from laser ablation seeding was investigated in a hydrogen/nitrogen non-premixed flame. The morphology and particle size distributions of the ablation products were examined with scanning electron microscopy and transmission electron microscopy. These investigations show that the ablation products comprise complex agglomerates of nano-sized primary particles of indium compounds and micron-sized spherical indium beads. Images of the atomic indium LIF, Mie scattering of ablation products and natural fluorescence emission of indium in the flame were recorded to investigate the mechanism of fluorescence signal generation. The relative contribution of natural fluorescence emission of indium towards the total indium fluorescence signal was assessed by comparing these images. These images also reveal the evolution of ablation products through the flame structure and the correlation between LIF signal and ablation products. It is found that the LIF signal generation is associated with the vapourisation of indium nanoparticles into the gas phase by thermal decomposition in the flame. A further mechanism for thermal decomposition of the nanoparticles was also identified, that of heating the ablation products by in situ laser ablation. This was assessed by means of a second laser, introduced prior to the excitation laser, to reveal that the LIF signal can be enhanced by in situ laser ablation, particularly in the upstream regions of the flame. These findings supersede the mechanism deduced previously by the authors that neutral atomic indium can survive a convection time of the order of tens of seconds and be directly seeded into reacting or non-reacting flows. The possible influences of laser ablation seeding on the nonlinear two-line atomic fluorescence thermometry technique were also assessed.

Plasmonic anisotropy of In nanocluster arrays on InAs(001) surface observed by differential reflectance spectroscopy

Reflectance anisotropy (RA) spectroscopy is applied to study indium nanocluster arrays formed on InAs(001) crystal surface by electrochemical treating. The measured RA spectra exhibit a resonant feature of negative sign whose scale ~10−1 exceeds by two orders of magnitude the scale of the related spectra conventionally observed for semiconductor surfaces. Plasmonic origin of the resonant feature is unambiguously established both experimentally and theoretically. The RA spectra of In nanoclusters covering InAs(001) surface are interpreted in terms of coupled dipole plasmons belonging to ellipsoidal metal nanoparticles. From the experimental RA spectra, an effective plasmonic anisotropy is estimated within a lattice model of indium nanoparticle coverage. It is concluded that the in-surface semi-axes of ellipsoids can differ by a few percent, as well as the periods of rectangular lattice occupied by nanoparticles.

External quantum efficiency response of thin silicon solar cell based on plasmonic scattering of indium and silver nanoparticles.

This study characterized the plasmonic scattering effects of indium nanoparticles (In NPs) on the front surface and silver nanoparticles (Ag NPs) on the rear surface of a thin silicon solar cell according to external quantum efficiency (EQE) and photovoltaic current–voltage. The EQE response indicates that, at wavelengths of 300 to 800 nm, the ratio of the number of photo-carriers collected to the number of incident photons shining on a thin Si solar cell was enhanced by the In NPs, and at wavelengths of 1,000 to 1,200 nm, by the Ag NPs. These results demonstrate the effectiveness of combining the broadband plasmonic scattering of two metals in enhancing the overall photovoltaic performance of a thin silicon solar cell. Short-circuit current was increased by 31.88% (from 2.98 to 3.93 mA) and conversion efficiency was increased by 32.72% (from 9.81% to 13.02%), compared to bare thin Si solar cells.