- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Tuning of surface plasmon resonance of silver nano particles by shock waves for plasmonic device applications
摘要： The present research article demonstrates the findings of the fine tuning of surface plasmon resonance (SPR) and the relationship between structural, optical and morphological properties of shock wave loaded silver nano-particles (Ag NPs). The characteristics of structural, optical and morphological properties of Ag NPs are evaluated by powder XRD (X-ray powder diffraction), UV–Vis (ultra violet- visible) spectroscopy and SEM (scanning electron microscopy) technique, respectively. The test material of Ag NPs is subjected to the shock wave loading with 50,100 and 150 shock pulses, respectively. The PXRD results reveal that the degree of crystalline nature and grain size of the crystal is significantly reduced by the impact of shock waves. The UV–Visible spectrum reveals that the control Ag NPs absorption band at 514 nm has given rise to blue shift (514–403 nm) at 150 shock wave loaded samples. The SEM images reveal that the particle size is considerably reduced by the impact of shock waves with respect to number of shock waves. The tri-angle correlation of structural, optical and morphological properties of shock wave loaded Ag NPs is explored.
关键词： Impact of shock waves,Tuning of SPR,Silver nano particles
更新于2025-09-23 15:21:01
-
Novel conducting PVA/Carbon quantum dots (CQDs) nanocomposite for high anti-electromagnetic wave performance
摘要： Novel conductive PVA/CQDs nanocomposite films were synthesized through the casting technique for the electromagnetic (EM) wave protection at microwave band. The surface morphology, thermal and mechanical properties were briefly studied. The SEM micrograph showed an excellent distribution, dispersion and a high adhesion property of the CQDs in the PVA chains. Also, DSC analysis showed an increase in the glass temperature (Tglass) from 83.2 °C for fresh PVA to 95.4 °C for 8 wt% of CQD and the increase in melting temperature from 215 °C for fresh PVA to 227.7 °C for the same CQDs concentration. It was found that Young's modulus is directly proportional to CQD nano-particles concentration in the nano-composites from 0.14 GPa for fresh PVA to 4.48 GPa for 8 wt% of CQDs. It was found that the strength at break increases, but the elongation declines with the increase of CQDs nano-particles. The EM shielding effectiveness (SE) of (PVA/CQDs) nanocomposite is measured in the microwave frequency range, and it is found around 36.8 dB with the CQDs concentration (8 wt%). Finally, the PVA/CQDs nano-composite is of promising potential applications in electronics and microwave devices at an affordable cost.
关键词： PVA,Mechanical properties,Electromagnetic shielding,Thermal properties,CQDs nano-particles
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - Atlanta, GA, USA (2019.7.7-2019.7.12)] 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - E-shaped Nano-antenna with Asymmetric Integrated Dielectric-plasmonic Waveguide
摘要： In this paper, a novel design of end-fire nano-antenna is introduced with higher directivity compared with previous works. To feed the designed nano-antenna by low loss dielectric waveguide, integrated dielectric-plasmonic waveguide is designed and by directional nano-particles inside the waveguide, directivity of the nano-antenna increases.
关键词： directional nano-particles,nano-antenna,integrated dielectric-plasmonic waveguide
更新于2025-09-16 10:30:52
-
Nano-Scaled Lanthanum Hexaboride (LaB6) – Control of Properties in Dependence on Type of Manufacturing
摘要： This paper presents the influence of fabrication methods on the optical and photo-thermal properties of nano-LaB6. The nano particles (NPs) were manufactured via continuously operated ball milling or induction plasma technology. Whereas different grinding processes for LaB6 were also discussed using ethylene glycol (EG) and ZrO2 grinding media in previous works, the scaled-up plasma technology presents a new possibility to gain NPs with high yields and narrow size distribution. In our work, NPs < 100 nm are achieved by grinding experiments using ethanol, 1-methoxy-2-propanol and ethylene glycol. Furthermore, the change of grinding parameters was investigated intensively. Compared to milled NPs, nano-LaB6 in high purity are gained by plasma technology and shows differences in color, morphology (UHR-FESEM), absorption behavior and crystallite size (X-Ray). Acrylate terminated starPEG (poly ethylene glycol) was used as a high cross-linked network after in-situ UV polymerization to stabilize NPs homogenously. We also set the focus on photo-thermal conversion properties of LaB6 dispersions in ethylene glycol, i.e. transformation of the absorbed photon energy into heat, and temperature distribution around the laser spot which are characterized by an IR camera.
关键词： photo-thermal conversion,top-down,ball milling LaB6,LaB6 nano particles,SPR,plasma LaB6,LaB6 stabilization
更新于2025-09-16 10:30:52
-
Metal nano-composite assisted photons harvesting in thin film organic photovoltaic
摘要： Nickel oxide (NiO) nano-particles assisted photons harvesting is studied using P3HT:PCBM blend based bulk heterojunction thin film organic solar cell (TFOSC). A comparison between devices that were fabricated at different concentration of NiO and that of the pristine P3HT:PCBM active layer were drawn up. The experimental results suggest that the incorporation of NiO in the solar absorber medium was found to be favourable for solar energy harvesting. At optimum concentration of NiO, in P3HT:PCBM blend active layer, the power conversion efficiency has grown by over 140% compared to the pristine type of devices. Moreover, significant improvement were also recorded on the solar cell fill factor (FF) and short circuit current density (JSC), respectively. The newly fabricated solar cells are discussed in terms of the optical and electrical properties of the solar absorber film.
关键词： Localized states,Solar cell,Nickel Oxide,Nano-composites,Nano-particles
更新于2025-09-12 10:27:22
-
Development of Textured Electrode, Index Matching Layer and Nanostructured Materials for Light Trapping inside Photovoltaic devices
摘要： In order to reduce the energy harvesting cost, numerous efforts have been made to replace crystalline silicon solar cells with thin film based solar cells. The device efficiency of thin film photo-voltaic devices needs to be improved. Currently, surface texturing based light trapping technologies have been used to improve the device efficiency of photo-voltaic devices. In this paper, we demonstrate experimentally that surface textured hydrogenated ZnO:Al films as transparent conducting oxide (TCO) electrode and nanostructured materials in solar cells improve the anti-reflection properties of TCO coated glass substrate. These surfaces scatter the incident light inside the active layer of solar cells. Scattering of light on textured and nanostructured surface causes increase in average light path length inside active layer which results in increased absorption coefficient. Amorphous silicon solar cells fabricated on textured TCO layer show increase in device efficiency. Silicon nitride film was used as index matching layer between glass and TCO and increase in transmittance was observed. Silicon nanowires were grown using PECVD for their application in solar cells. Metal (Indium) nanoparticles were used for plasmonic light trapping inside solar cells. It was observed that textured TCO, index matching layer and plasmonic nanoparticles techniques improve the device efficiency while nanowires based devices need more optimization to get higher efficiency.
关键词： Plasmonic Light Trapping,Nano-Particles,Thin Film Solar Cell,Surface Texturing,Silicon Nanowires
更新于2025-09-12 10:27:22
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Plasmonic Random Laser with the Embedding of Silver Nanostructure Materials
摘要： In contrast to conventional lasers, random lasers (RLs), without cavity mirrors, were generated based on recurrent light scattering within nano-materials and possessed peculiar properties for practical applications. To date, researchers are not only interested in the novel nano-materials for the generation of RL but also curious in the manipulated property of RL through temperature and electric filed [1]. In addition, plasmonic random laser (PRL)[2] based on the localized surface plasmon resonance (LSPR) of metallic nanoparticles has attracted great interest. In this work, the dye-covered PVA (DC-PVA) film with the embedding of silver nano-particles (AgNPs) was produced to investigate the enhancement of emission spike intensity from PRL and the underlying mechanism by varying the size and shape of AgNPs. Here, the AgNPs were synthesized by a soft solution-phase approach inside the DI water [3]. Depending on the size and shape of AgNPs in colloidal solution, the absorbance spectrum in Fig. 1(a) reveals different peak absorption wavelength (λp) at 404 nm and 610 nm, respectively, and shows deep yellow and navy color (Fig. 1(a)). The PVA film with embedding of AgNPs (PVA/AgNPs) was produced by dropping the mixed solution, comprising PVA powder and AgNPs, onto a glass substrate. After drying, the laser dye (Pyrromethene 597, Exciton inc.) was coated on the top of PVA film (Inset of Fig. 1: the structure of sample). In this work, the coherent back scattering measurement (CBS) measurement [4] was performed to obtain the transport mean free path (lp) of pure DC-PVA film (green squares: Sample-I) and DC-PVA/AgNP film [red triangles: Sample-II (λp at 405 nm), blue circle: Sample-III (λp around 610 nm)]. The solid lines represent the theoretical fitting curves to obtain the lp of three samples around 10.3, 8.7 and 3.6 μm. The value of lp decreases obviously after AgNPs was embedding in the PVA film to illustrate the enhancement of light scattering. In order to generate RL, we excited all the produced samples by a frequency doubling Q-switched Nd:YAG laser with a central wavelength of 532 nm. The 10 Hz pump pulses were focused onto the sample with a long line stripe by a cylindrical lens with focal length f = 7cm. The side emission of the sample was collected by the fiber tip and measured by the spectrometer (resolution about 0.3 nm, Ocean Optics Inc.). Inset of Fig. 1(b) shows the emission spectra of DC-PVA film without (Sample-I, green solid curve) and with (Sample-II: red solid curve and Sample-III: blue solid curve) AgNPs. Even at relatively high pulse energy, the Sample-I (without AgNPs) only reveals broad spontaneous emission spectrum with the maximum intensity at λ = 578 nm. For the sample-II and sample-III (DC-PVA/AgNP film), the discrete emission spikes at around about λ=576 and 583 nm on the top of broad spontaneous emission can be revealed which is the characteristic of RL. In order to qualitatively distinguish the operation state of RL, the α-stable distribution [5] proposed by Uppu et al. was used to analysis the intensity fluctuation (red) of the sample by sampling 1000 spectrum slots. The intensity distribution (red histogram) can be theoretical fitting by the equation (blue solid curves in Figs. 1(c) and 1(d)) to obtain the α=1.99 and 1.58, respectively, which reveals the Gaussian and Levy distribution.
关键词： random lasers,light scattering,localized surface plasmon resonance,plasmonic random laser,silver nano-particles
更新于2025-09-12 10:27:22
-
Characterisation and photocatalytic assessment of TiO2 nano-polymorphs: Influence of crystallite size and influence of thermal treatment on paint coatings and dye fading kinetics
摘要： A study on the thermal effects on TiO2 rutile and anatase nano-powders was undertaken and displayed some unusual photoactivity and crystal structure properties. Rutile nano-particles with different crystallite sizes were characterised and the possible effect on activity were investigated. One of the rutile samples appeared to have trace amounts of anatase and was annealed at high temperatures at 1172 K and 1272 K to highlight the thermodynamic stability phenomenon of titania. Parallel to this study, anatase nano-particles were investigated before and after being annealed up to 1022 K. For all the samples used in this work, characterisation was undertaken using micro-Raman microscopy/XRD and Scanning Electron Microscopy (SEM) while photoactivity assessment was made by measuring and monitoring the photodegradation of a mixture of dye methyl-orange (MeO) and nano-powders under UV-light for 3h30 minutes in suspension. The study revealed that rutile nano-powder samples were thermodynamically stable even at very high temperatures and poorly active but with an unusual photoactive feature. Concerning the anatase samples; SEM investigation revealed a questioning size growth as the samples showed a different particle size depending on the temperature of thermal treatment. It revealed that annealing at 672 K seemed to be a key temperature as the particles change from a polyhedral structure to a two-dimensional structure showing a platelet like shape. The photocatalytic studies of the anatase nano-particles showed a very high activity especially before annealing. This highlighted the fact that the anatase phase can subsist at high temperatures such as 1022 K and exhibit a persistence in photoactivity even though it has decreased significantly after 672 K. SEM analysis was in accordance with the photoactivity investigation. Nevertheless, the most interesting feature of the results emanates from the reaction order study and rate constant analysis taken from the kinetic shape of the graph of the degradation of MeO as a function of the irradiation time for the different particle sized rutile nanoparticles. Here a zero-order reaction was determined and as a consequence raised questions about the theory of the mechanism of the activities of titania in terms of surface chemistry, surface area dependence and photoactivity. For example, for the nano-rutiles the sample with a 25 nm crystallite size was the most active and the sample with the smallest crystallite size (15nm) was the least active and yet was found to contain trace levels of nano-anatase. This effect was also substantiated by UV absorption and weathering studies on doped isocyanate-acrylic paint films. UV analysis clearly shows that the absorptivity of the nanoparticles plays a role and correlates with the photoactivity. The 15nm particles have decreased absorptivity in the near UV and hence decreased activity.
关键词： nano-particles,titanium dioxide,crystal size,temperature treatment,anatase,isocyanate-acrylic paint,methyl orange,rutile,photocatalysis
更新于2025-09-09 09:28:46
-
AIP Conference Proceedings [AIP Publishing LLC NANOFORUM 2014 - Rome, Italy (22–25 September 2014)] - Impact of energy injection on size of Al nanoparticles generated by electric explosion of metal foils
摘要： The process of electric explosion of Aluminium metal foil has been used to produce nano aluminium powder under ambient atmospheric conditions. The impact of average rate of energy injection and overheat factor on size distribution of particles was analyzed by TEM technique. It was observed that higher the rate of energy deposition, the smaller the particles formed.
关键词： overheat factor,Nano particles,Pulse discharge
更新于2025-09-09 09:28:46
-
Ag/TiO <sub/>2</sub> NPs/TiO <sub/>2</sub> TF/Si Based Non-Volatile Memristor Device for Neuromorphic Computing Applications
摘要： Memristor device is a very promising emerging component for a revolution of the memory and computing applications in the recent years. It could be enhancing the field of artificial intelligence and helping the patients, suffering from various kinds of autism disorders, as well as in neuromorphic computing, neural networks, etc. This research article proposes fabricated non-volatile memristor device for neuromorphic computing applications. The demonstrate memory is based on Ag/TiO2 NPs/TiO2 TF/Si layers’ structure and achieves better conductivity and storage capacity, which could improve the performance of the neuromorphic computing as compared to conventional ones. The fabrication method of the proposed multi-layer memristor is examine with well precise techniques, which overcome the previous challenges. The surface morphology of the device is analysed by field emission gun scanning electron microscopy (FEGSEM) and Energy dispersive X-ray system. The rise time (Tr) of 2.5 s and fall time (Tf) of 3 s are demonstrated under ON/OFF white light illumination. While X-ray diffraction depicted that titanium dioxide nano particle, (TiO2 NPs) are crystalline in nature. Moreover, Photoluminescence and Raman analysis justify crystalline nature also and increasing oxygen vacancies concentration with the heating effect of TiO2 NPs. The electrical analysis reveals the driving mechanism under different sweeping voltages during SET and RESET resulting in low resistance state (‘ON’). Finally, capacitance-voltage characteristic of the proposed memory device shows excellent charge storage capacity within the dynamic range of operation.
关键词： Titanium Dioxide Nano Particles (TiO2 NPs),Memristor Devices,Neuromorphic Computing,Titanium Dioxide Thin Film (TiO2 TF)
更新于2025-09-09 09:28:46