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Synthesis, characterization and UV photodetector application of Sb-doped ZnO nanowires
摘要： Sb-doped ZnO nanowires with hexagonal wurtzite structures have been synthesized via chemical vapor deposition method, and the main charge state of Sb dopants is Sb5+. The photoluminescence spectra demonstrate the existence of shallow acceptors, SbZn-2VZn complexes in all probability. On the other hand, Sb doping caused more native and impurity donors in Sb-doped ZnO nanowires. Then, field effect transistors of single Sb-doped ZnO nanowire were fabricated and the transport properties shows n-type conductivity. The competition between shallow acceptors and donors, and the influence of Sb valency need to be investigated further to obtain stable Sb-doped p-type ZnO. At last, we have shown the potential application of Sb-doped ZnO nanowires for nanoscale UV photodetector.
关键词： field effect transistors,UV photodetector,Sb-doped ZnO nanowires,photoluminescence,chemical vapor deposition
更新于2025-09-16 10:30:52
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Sensitivity Enhancement of a Concave Shaped Optical Fiber Refractive Index Sensor Covered with Multiple Au Nanowires
摘要： In the present paper, a new kind of concave shaped refractive index sensor (CSRIS) exploiting localized surface plasmon resonance (LSPR) is proposed and numerically optimized. The LSPR effect between polaritons and the core guided mode of designed CSRIS is used to enhance the sensing performance. The sensor is characterized for two types of sensing structures coated with gold (Au) film and Au nanowires (AuNWs), respectively. The influence of structural parameters such as the distance (D) of the concave shaped channel (CSC) from the core, the diameter of the nanowire (dn) and the size (s) of the CSC are investigated here. In comparison to Au film, the AuNWs are shown to significantly enhance the sensitivity and the performance of the designed sensor. An enhanced sensitivity of 4471 nm/RIU (refractive index unit) is obtained with AuNWs, for a wide range of analytes refractive index (na) varying between 1.33 to 1.38. However, for conventional Au film; the sensitivity of 808.57 nm/RIU is obtained for the same range of analytes.
关键词： nanowires,microfluidic channel,surface plasmon resonance,sensitivity,refractive index
更新于2025-09-16 10:30:52
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SiNW/C@Pt Arrays for High-Efficiency Counter Electrodes in Dye-Sensitized Solar Cells
摘要： Modern energy needs and the pressing issue of environmental sustainability have driven many research groups to focus on energy-generation devices made from novel nanomaterials. We have prepared platinum nanoparticle-decorated silicon nanowire/carbon core–shell nanomaterials (SiNW/C@Pt). The processing steps are relatively simple, including wet chemical etching to form the silicon nanowires (SiNWs), chemical vapor deposition to form the carbon shell, and drop-casting and thermal treatment to embed platinum nanoparticles (Pt NPs). This nanomaterial was then tested as the counter electrode (CE) in dye-sensitized solar cells (DSSCs). SiNW/C@Pt shows potential as a good electrocatalyst based on material characterization data from Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectroscopy shows that the surface reactivity of the SiNW/C is increased by the decoration of Pt NPs. These data also show that the carbon shell included both graphitic (sp2 hybridization) and defective (sp3 hybridization) phases of carbon. We achieved the minimum charge-transfer resistance of 0.025 ? · cm2 and the maximum ef?ciency of 9.46% with a symmetric dummy cell and DSSC device fabricated from the SiNW/C@Pt CEs, respectively.
关键词： core–shell,defective carbon,electrocatalytic activity,dye-sensitized solar cells (DSSCs),counter electrodes (CEs),silicon nanowires (SiNWs)
更新于2025-09-16 10:30:52
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Synthesis and characterization of PEDOT:PSS/ZnO nanowires heterojunction on ITO coated plastic substrate for light-emitting diodes
摘要： In this paper we report on heterojunction between the hole transporting polymerpoly (3, 4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) and zinc oxide (ZnO) nanowires grown on an indium tin oxide (ITO) coated polyethylene terephthalate (PET) plastic substrate. For the fabrication of heterojunction simple and low cost solution methods are used. The deposited films and heterojunction are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), photoluminescence (PL) and electroluminescence (EL) measurements. Electroluminescent and photoluminescent spectra of the hybrid heterojunction show one ultraviolet (UV) near-band-edge emission peak. The current-voltage characteristic confirms the junction formation between the polymer and ZnO nanowires and shows good rectifying p-n junction diode type behaviour of the fabricated structure. The charge transfer process in heterojunctionis explained by band energy diagram.
关键词： ZnO nanowires,PEDOT: PSS,flexible electroluminescent diode,p-n- heterojunction
更新于2025-09-16 10:30:52
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Monotectic growth evolution and raman scattering of self-assembled ZnO hierarchical micro-nanostructures
摘要： The self-assembled hierarchical micro-nanostructures with geometric complexity and/or constituent diversity are becoming a promising class of candidates for the next generation nanotechnology. Different from conventional vapor-liquid-solid (VLS) eutectic liquid droplets for one-dimensional (1D) nanowires, the Zn-Bi VLS monotectic liquid droplets are employed to build 1D, 2D and 3D ZnO into 3D hierarchical micro-nanostructures. As-obtained micro-nanostructures are well de?ned self-assembly and have not yet been observed in the conventional eutectic alloys. The synergy of monotectic droplets and nonthermal equilibrium is responsible for the evolution of ZnO hierarchical micro-nanostructures. Raman spectra show that E2H and E1L modes are shifted slightly towards the high-wavenumber side by an amount of 3.7 and 2 cm?1 as compared with undoped ZnO nanowires and an additional peak at 519.5 cm?1 is associated with Bi38OZn60. The results manifest that 3D ZnO micro-nanoarchitectures possess a bulk phonon structure. The monotectic liquid droplet route presented in this paper may offer a new opportunity to the fabrication of hierarchical nanostructures for realistic technology platforms with multifunctional coupling and interplay.
关键词： nanowires,growth mechanism,nanofabrications,nanostructures,Raman scattering
更新于2025-09-16 10:30:52
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Highly Efficient Flexible Perovskite Light-Emitting Diodes Using Modified PEDOT:PSS Hole Transport Layer and Polymer-Silver Nanowires Composite Electrode
摘要： Metal halide perovskites have been actively studied as promising materials in optoelectronic devices because of their superior optical and electrical properties, and have also shown considerable potential for flexible devices because of their good mechanical properties. However, the large hole injection barrier and exciton quenching between the perovskite emitter and poly(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS) can lead to the reduction in device efficiency. Here, a nonconductive fluorosurfactant, Zonyl FS-300 (Zonyl), is introduced into the PEDOT:PSS hole transport layer, which reduces the hole injection barrier and exciton quenching at the PEDOT:PSS/perovskite interface. Moreover, a flexible perovskite light-emitting diode with a polymer–silver nanowire composite electrode is demonstrated, showing a maximum current efficiency (CEmax) of 17.90 cd A–1, and this is maintained even after 1,000 cycles of bending with a 2.5 mm bending radius.
关键词： flexible perovskite light-emitting diodes,hole transport layer,flexible electrode,silver nanowires (AgNWs),poly(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS)
更新于2025-09-16 10:30:52
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High-Performance Transparent Ultraviolet Photodetectors Based on InGaZnO Superlattice Nanowire Arrays
摘要： Due to the efficient photocarrier separation and collection coming from their distinctive band structures, superlattice nanowires (NWs) have great potential as active materials for high-performance optoelectronic devices. In this work, InGaZnO NWs with superlattice structure and controllable stoichiometry are obtained by ambient-pressure chemical vapor deposition (CVD). Along the NW axial direction, perfect alternately stacking of InGaO(ZnO)4+ blocks and InO2- layers is observed to form a periodic layered structure. Strikingly, when configured into individual NW photodetectors, the Ga concentration is found to significantly influence the amount of oxygen vacancy and oxygen molecules adsorbed on the NW surface, which dictate the photoconducting properties of the NW channels. Based the optimized Ga concentration (i.e. In1.8Ga1.8Zn2.4O7), the individual NW device exhibits an excellent responsivity of 1.95×105 A/W and external quantum efficiency of as high as 9.28×107 % together with a rise time of 0.93 s and a decay time of 0.2 s for the ultraviolet (UV) photodetection. Besides, the obtained NWs can be fabricated into large-scale parallel arrays on glass substrates as well to achieve the fully-transparent UV photodetectors, where the performance is on the same level or even better than many transparent photodetectors with high performance. All the results discussed above demonstrate the great potential of InGaZnO superlattice NWs for next-generation advanced optoelectronic devices.
关键词： superlattice,InGaZnO,nanowires,transparent,ultraviolet photodetectors
更新于2025-09-16 10:30:52
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Facile synthesis and characterization of V2O5 nanobelt bundles containing plasmonic Ag for photoelectrochemical water splitting under visible light irradiation
摘要： V2O5 nanobelt bundle (NBB) photoanodes were synthesized from commercial V2O5 powder via a facile, room-temperature aqueous solution technique. The V2O5 NBBs were several micrometers long and 15–25 nm wide, with an orthorhombic V2O5 structure, a crystallite size of 63 nm, and an optical bandgap of 2.19 eV. The V2O5 NBBs containing plasmonic Ag showed signi?cantly lower charge transfer resistance than the pure V2O5 NBBs. The charge transfer resistance was further reduced to 21.02 Ω by adding 10% methanol to the 0.1 M KOH electrolyte as a hole scavenger. The water-splitting activity of the V2O5 and V2O5/Ag photoanodes was tested in 0.1 M KOH; a very low photocurrent density of 0.5 μA/cm2 was observed under visible light illumination. The low photocurrent was ascribed to a build-up of photogenerated holes at the photoelectrode/aqueous electrolyte. The addition of methanol drastically increased the photocurrent of the V2O5 NBB photoelectrode. A maximum photocurrent density of 0.2 mA/cm2 was achieved for up to 230 s under light illumination for the V2O5 NBBs containing plasmonic Ag in KOH and methanol, which was 400 times higher than that of the photoanode without a hole scavenger.
关键词： Aqueous electrolyte,Nanowires,Hole scavenger,Ag plasmonic,Water splitting activity
更新于2025-09-16 10:30:52
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Controlled growth of single-crystalline metal nanowires via thermomigration across a nanoscale junction
摘要： Mass transport driven by temperature gradient is commonly seen in fluids. However, here we demonstrate that when drawing a cold nano-tip off a hot solid substrate, thermomigration can be so rampant that it can be exploited for producing single-crystalline aluminum, copper, silver and tin nanowires. This demonstrates that in nanoscale objects, solids can mimic liquids in rapid morphological changes, by virtue of fast surface diffusion across short distances. During uniform growth, a thin neck-shaped ligament containing a grain boundary (GB) usually forms between the hot and the cold ends, sustaining an extremely high temperature gradient that should have driven even larger mass flux, if not counteracted by the relative sluggishness of plating into the GB and the resulting back stress. This GB-containing ligament is quite robust and can adapt to varying drawing directions and velocities, imparting good controllability to the nanowire growth in a manner akin to Czochralski crystal growth.
关键词： single-crystalline,surface diffusion,nanowires,grain boundary,thermomigration
更新于2025-09-16 10:30:52
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TiO2 hierarchical nanowire-P25 particulate composite photoanodes in combination with N-doped mesoporous carbon/Ti counter electrodes for high performance quantum dot-sensitized solar cells
摘要： The time-consuming transport of photo-generated electrons across conventional photoanode film, composed of disordered P25 TiO2 nanoparticulates, is one of the main bottlenecks to improve the performance of quantum dot-sensitized solar cells (QDSCs). A convenient and effective method was developed for the preparation of high performance photoanodes based on composite paste composed of conventional P25 TiO2 nanoparticulates and TiO2 hierarchical nanowires (HNW) for QDSCs. The shortened transport path in the composite photoanode brings forward suppressed charge recombination processes at the interfaces between photoanode and electrolyte, and improved photovoltaic performance of the resulting solar cells. Through optimizing the composite photoanode and the adoption of N-doped mesoporous carbon/Ti counter electrodes, average power conversion efficiency of Zn-Cu-In-Se (ZCISe) QDSCs was increased from 12.77% corresponding to conventional P25 photoanodes to 13.43% (Jsc = 27.38 mA cm?2, Voc = 0.764 V, and FF = 0.642) corresponding to photoanodes with HNW/P25 weight ratio of 0.1%. Furthermore, this composite photoanode is also effective in improving the photovoltaic performance of QDSCs under different QD sensitizers (such as Zn-Cu-In-S (ZCIS) QDs) as well as different counter electrodes (such as Cu2S/brass).
关键词： TiO2 hierarchical nanowires,Quantum dot-sensitized solar cells,Composite photoanode,High efficiency
更新于2025-09-16 10:30:52