共查询到20条相似文献，搜索用时 15 毫秒
1.
Tristan L. Temple Darren M. Bagnall 《Progress in Photovoltaics: Research and Applications》2013,21(4):600-611
Metal nanoparticles offer the possibility of improved light trapping in solar cells, but careful design is required to maximise scattering and minimise parasitic absorption across the wavelength range of interest. We present an analysis of the broadband scattering and absorption characteristics of spherical metal nanoparticles, optimized for either crystalline silicon (c‐Si) or amorphous silicon (a‐Si:H) solar cells. A random two‐dimensional array of optimally sized Ag spheres can scatter over 97% of the AM1.5 spectrum from 400 to 1100 nm. Larger particles are required for c‐Si devices than a‐Si:H due to the increased spectral range, with optimum particle sizes ranging from 60 nm for a‐Si:H to 116 nm for c‐Si. Positioning the particles at the rear of the solar cell decreases absorption losses because these principally occur at short wavelengths. Increasing the refractive index of the surrounding medium beyond the optimum value, which is 1.0 for a‐Si:H and 1.6 for c‐Si, shifts absorption to longer wavelengths and decreases scattering at short wavelengths. Ag nanoparticles scatter more of the solar spectrum than Au, Cu or Al nanoparticles. Of these other metals, Al can only be considered for a‐Si:H applications due to high absorption in the near‐infrared, whereas Au and Cu can only be considered for the rear of c‐Si devices due to high absorption in the ultraviolet (UV) and visible. In general, we demonstrate the importance of considering the broadband optical properties of metal nanoparticles for photovoltaic applications. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
2.
《Advanced functional materials》2018,28(37)
Magnetic hyperthermia (MHT) and photothermal therapy (PTT) are emergent state‐of‐the‐art modalities for thermal treatment of cancer. While their mechanisms of action have distinct physical bases, both approaches rely on nanoparticle‐mediated remote onset of thermotherapy. Yet, are the two heating techniques interchangeable? Here, the heating obtained either with MHT or with PTT is compared. The heating is assessed in distinct environments and involves a set of nanomaterials differing in shape (spheres, cubes, stars, shells, and rods) as well as in composition (maghemite, magnetite, cobalt ferrite, and gold). The nanoparticle's heating efficacy in an aqueous medium is first evaluated. Subsequently, the heating efficiency within the cellular environment, where intracellular processing markedly decreases MHT, is compared. Conversely, endosomal sequestration could have a positive effect on PTT. Finally, iron oxide nanocubes and gold nanostars are compared in MHT and PTT in vivo within the heterogeneous intratumoral environment. Overall, two distinct therapeutic approaches, related to high dosage allowing MHT and low dosage associated with PTT, are identified. It is also demonstrated that PTT mediated by magnetic nanoparticles has an efficacy that is comparable to that of plasmonic nanoparticles, but only at significant nanoparticle dosages. At low concentrations, only plasmonic nanoparticles can deliver a therapeutic heating. 相似文献
3.
Qian Li Feiliang Chen Jianbin Kang Juan Su Feng Huang Pidong Wang Xiu Yang Yidong Hou 《Advanced functional materials》2021,31(18):2010537
Counterfeit electronics are a growing problem for the electronic information industry worldwide, so developing unbreakable security tags is crucial to ensure the trustworthiness and traceability of electronics. Traditional anticounterfeiting and trace solutions rely on reproducible deterministic processes and additional labels, which can still be copied or faked by counterfeiters. Herein, physical unclonable functions enabled by spontaneously formed plasmonic core–shell nanoparticles on electrodes are proposed to ensure label-free traceable electronics, giving a practical solution to fight against counterfeit electronics. Random hemispherical core–shell nanoparticles are intentionally introduced on the metal electrode of different semiconductors (Si, GaAs, and GaN) from Ni/Au bilayer heterofilms by rapid thermal annealing, which can be integrated with electronics seamlessly, with no negative effect on electrical properties. The position, size, and shape of nanoparticles are random and uncontrollable; the corresponding scattering patterns, intensity, and spectra can work as nanofingerprints of the electrode, proving multidimensional unclonable labels with large encoding capacity suitable for electrodes smaller than several micrometers. It can be further combined with machine vision and artificial intelligence to identify and track electronics automatically and efficiently. The anticounterfeiting electrodes also show good thermal robustness and mechanical stability, opening up a prospect for practical anticounterfeiting of electronics. 相似文献
4.
Swagato Sarkar Vaibhav Gupta Takuya Tsuda Jeetendra Gour Arvind Singh Olha Aftenieva Anja M. Steiner Marisa Hoffmann Sunil Kumar Andreas Fery Joby Joseph Tobias A.F. König 《Advanced functional materials》2021,31(19):2011099
The challenges in plasmonic charge transfer on a large-scale and low losses are systematically investigated by optical designs using 1D-plasmonic lattice structures. These plasmonic lattices are used as couplers to guide the energy in an underneath sub-wavelength titanium dioxide layer, resulting in the photonic crystal slabs. So far, photodetection is possible at energy levels close to the semiconductor bandgap; however, with the observed hybrid plasmonic–photonic modes, other wavelengths over the broad solar spectrum can be easily accessed for energy harvesting. The photo-enhanced current is measured locally with simple two-point contact on the centimeter-squared nanostructure by applying a bias voltage. As lattice couplers, interference lithographically fabricated conventional gold grating provides an advantage in fabrication; this optical concept is extended for the first time toward colloidal self-assembled nanoparticle chains to make the charge injection accessible for large-scale at reasonable costs with possibilities of photodetection by electric field vectors both along and perpendicular to the grating lines. To discuss the bottleneck of unavoidable isolating ligand shell of nanoparticles in contrast to the directly contacted nanobars, polarization-dependent ultrafast characterizations are carried out to study the charge injection processes in femtosecond resolution. 相似文献
5.
Michael Saliba Wei Zhang Victor M. Burlakov Samuel D. Stranks Yao Sun James M. Ball Michael B. Johnston Alain Goriely Ulrich Wiesner Henry J. Snaith 《Advanced functional materials》2015,25(31):5038-5046
Organic–inorganic metal halide perovskite solar cells have emerged in the past few years to promise highly efficient photovoltaic devices at low costs. Here, temperature‐sensitive core–shell Ag@TiO2 nanoparticles are successfully incorporated into perovskite solar cells through a low‐temperature processing route, boosting the measured device efficiencies up to 16.3%. Experimental evidence is shown and a theoretical model is developed which predicts that the presence of highly polarizable nanoparticles enhances the radiative decay of excitons and increases the reabsorption of emitted radiation, representing a novel photon recycling scheme. The work elucidates the complicated subtle interactions between light and matter in plasmonic photovoltaic composites. Photonic and plasmonic schemes such as this may help to move highly efficient perovskite solar cells closer to the theoretical limiting efficiencies. 相似文献
6.
Yidong Hou Ho Ming Leung Che Ting Chan Jinglei Du Helen Lai‐Wai Chan Dang Yuan Lei 《Advanced functional materials》2016,26(43):7807-7816
Low‐cost and large‐scale fabrication of 3D chiral metamaterials is highly desired for potential applications such as nanophotonics devices and chiral biosensors. One of the promising fabrication methods is to use glancing angle deposition (GLAD) of metal on self‐assembled dielectric microsphere array. However, structural handedness varies locally due to long‐range disorder of the array and therefore large‐scale realization of the same handedness is impossible. Here, using symmetry considerations a two‐step GLAD process is proposed to eliminate this longstanding problem. In the proposed scheme, the unavoidable long‐range disorder gives rise to microscale domains of the same handedness but of slightly different structural geometries and ultimately contributes to a broad‐band response. Experimentally, a record‐breaking superchiral response of circular dichroism signal of ≈11° is demonstrated and an average polarization rotation angle of 27° in the visible region on ≈1 cm2 sample is observed. Computer‐aided geometric reconstruction with experimental parameters unambiguously reveal the presence of strong structural anisotropy and chirality in the prepared stacked‐patch plasmonic chiral metamaterial; microscopic spectral analyses combined with full‐wave electromagnetic simulations coherently provide deeper insights into the measured circular dichroism and optical activity. The observed chiroptical response can also be flexibly controlled by adjusting the deposition parameters for various potential applications. 相似文献
7.
Chengliang Duan Bin Wang Jinpeng Li Jinsong Zeng Daxian Cao Jun Xu Wenhua Gao Kefu Chen 《Advanced functional materials》2024,34(25):2315865
The microscopically structural switching of supramolecular networks endows programmable gel materials with dynamic hiding properties and functionalities. However, the reconstruction of supramolecular network will destroy the programming information imprinted on the original network structure, making it difficult to restore to the original state. Here, a novel intelligent programmable photonic gel composed of cellulose nanocrystals (CNC) and acrylamide is constructed. The mechanical properties and optical signals of gel can be switched reversibly on demand by reasonably designing the winding and compression between molecular structures. Under this conversion mechanism, the rigid “skeleton” constructed from the CNC chiral structure perfectly acts as the coding substrate. Importantly, even after multiple dynamic switching of the supramolecular network, the encoded information can be displayed completely and accurately on the CNC chiral structure in the stretched state. In addition, the 5D controllable conversion of stiffness, transparency, stretchability, color, and shape greatly improves the security and confidentiality of the encoded information inside the gel. This is a successful example of the application of CNC chiral structure in switchable supramolecular network materials. It is believed that the flexible variability and advanced camouflage give the intelligent gel the potential to be used in a wider range of practical scenarios. 相似文献
8.
Thi Kim Oanh Vu Thi Thu Phuong Bui Ngoc Anh Nguyen Thi Thanh Bao Nguyen Thi Minh Hien Nguyen Eun Kyu Kim 《半导体学报》2024,45(12):122301-1-122301-7
Recently, there has been considerable interest in high-efficiency ultraviolet (UV) photodetectors for their potential practical uses. In this study, a high-quality UV photodetector was fabricated using a combination of Ag and Au NPs with GaN film. The GaN film was deposited using sputtering technique, whereas Ag and Au films were grown using thermal evaporation technique. Ag−Au bimetallic nanoparticles were formed by treating them at the various annealing temperature to improve the interaction between light and the photoactive layers of the photodetectors. The optimal annealing temperature to achieve the best performance of a photodetector is 650 °C. This led to a photoresponsivity of 98.5 A/W and the ON/OFF ratio of 705 at low bias voltage of 1 V. This work establishes the foundation for the advancement of high-performance UV photodetectors. 相似文献
9.
Georgios A. Sotiriou Christoph O. Blattmann Sotiris E. Pratsinis 《Advanced functional materials》2013,23(1):34-41
Filler nanoparticles greatly enhance the performance of polymers and minimize filler content in the resulting nanocomposites. At the same time, they challenge the manufacturing of such nanocomposites by filler agglomeration and non‐uniform spatial distribution. Here, multifunctional nanocomposite films are made by capitalizing on flame‐synthesis of ceramic or metal filler nanoparticles followed by rapid, in situ deposition on sacrificial substrates, resulting in a filler film with controlled porosity. The polymer is then spin‐coated on the porous film that retained its stochastic but uniform structure, resulting in nanocomposites with homogeneous filler distribution and high filler‐loading. By sequential repetition of this procedure, sophisticated, multilayer, free‐standing, plasmonic‐ (Ag‐Fe2O3) and phosphorescent‐superparamagnetic (Y2O3:Eu3+‐ Fe2O3) actuators are made by precisely tuning the polymer thickness between each functional nanostructured layer. These actuators are quite flexible, have fast response times, and exhibit superior superparamagnetism due to their high filler content and homogeneous spatial distribution. 相似文献
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11.
Mohamed Shehata Draz Ying‐Jie Wang Frank Fanqing Chen Yuhong Xu Hadi Shafiee 《Advanced functional materials》2017,27(5)
The promise of DNA vaccines is far‐reaching. However, the development of potent immunization methods remains a key challenge for its use in clinical applications. Here, an approach for in vivo DNA vaccination by electrically activated plasmonic Au nanoparticles is reported. The electrical excitation of plasmonic nanoparticles can drive vibrational and dipole‐like oscillations that are able to disrupt nearby cell membranes. In combination with their intrinsic ability to focus and magnify the electric field on the surface of cells, Au nanoparticles allow enhanced cell poration and facilitate the uptake of DNA vaccine. Mice immunized with this approach showed up to 100‐fold higher gene expression compared to control treatments (without nanoparticles) and exhibited significantly increased levels of both antibody and cellular immune responses against a model hepatitis C virus DNA vaccine. This approach can be tuned to establish controlled and targeted delivery of different types of therapeutic molecules into cells and live animals as well. 相似文献
12.
Changli Lü Junfang Gao Yuqin Fu Yaying Du Yongli Shi Zhongmin Su 《Advanced functional materials》2008,18(19):3070-3079
A facile ligand exchange approach for surface‐functionalized ZnS nanoparticles (NPs) with 5‐(2‐methacryloylethyloxymethyl)‐8‐quinolinol (MQ) is described. The MQ–ZnS NPs, with a cubic crystal structure, have the same diameter as ZnS NPs without MQ about 3.0 nm. The MQ–ZnS NPs exhibit strong fluorescence emission at about 500 nm and a high photoluminescence (PL) quantum yield (QY), up to 40%, with a decreasing ratio of MQ to ZnS NPs. The PL decay study reveals that the lifetimes of the different MQ–ZnS NPs with a single exponential decay are in the nanosecond time domain for emission at about 500 nm, which is obviously different from that of ZnS NPs with a biexponential decay for defect‐state emission at 420 nm. The functionalized MQ–ZnS NPs are successfully incorporated into the polymer matrix by in situ bulk polymerization to fabricate transparent bulk nanocomposites with good thermal stability and processability. Transmission electron microscopy results show that the NPs are uniformly dispersed in the polymer matrix without aggregation. The good PL properties of MQ–ZnS NPs are preserved in the bulk nanocomposites. It is observed that the nanocomposites have red‐shifted excitation and emission wavelengths compared with those of both the polymer matrix and MQ–ZnS NPs, possibly because of the cooperative interaction between MQ–ZnS NPs and the polymer matrix with blue emission. 相似文献
13.
Christoph Sikeler Franziska Haslinger Irina V. Martynenko Tim Liedl 《Advanced functional materials》2024,34(42):2404766
Plasmonic nanostructures are frequently utilized to create metasurfaces with a large variety of optical effects. Control over shape and positioning of the nanostructures is key to the function of such plasmonic metasurfaces. Next to lithographic means, directed self-assembly is a viable route to create plasmonic structures on surfaces with the necessary precision. Here, a combined approach of DNA origami self-assembly and electron beam lithography is presented for determinate positioning of gold nanospheres on a SiO2 surface. First, DNA origami structures bind to the electron beam-patterned substrate and subsequently, gold nanoparticles attach to a defined binding site on the DNA origami structure via DNA hybridization. A sol-gel reaction is then used to grow a silica layer around the DNA, thereby increasing the stability of the self-assembled metasurface. A mean yield of 74% of single gold nanospheres is achieved located at the determinate positions with a spatial position accuracy of 9 nm. Gold nanosphere dimers and trimers are achieved with a rate of 65% and 60%, respectively. The applicability of this structuring method is demonstrated by the fabrication of metasurfaces whose optical response can be tuned by the polarization of the incoming and the scattered light. 相似文献
14.
The photoluminescence intensity of the dodecanethilol-functionalized Au (DDT-Au) nanoparticle (NP) layer/4,4′-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC)/4,4′-bis(N-carbazolyl)-1,1′-biphenyl:tris(2-phenylpyridine)iridium (III) (CPB:Ir(ppy)3) film was increased by about 1.15 times compared to that of the TAPC/CPB:Ir(ppy)3 film due to the effect of coupling between the excitons in the emitting layer and a localized surface plasmonic resonance (LSPR) in the DDT-Au NPs. The current efficiency of the organic light-emitting devices (OLEDs) with the DDT-Au NP layer at 100 cd/m2 was 14.9 cd/A larger than that without the DDT-Au NP layer, resulting in an enhancement of the out-coupling efficiency. The increase in the current efficiency of the OLEDs with a DDT-Au NP layer was attributed to the enhanced out-coupling efficiency due to the existence of the LSPR generated by the DDT-Au NPs. 相似文献
15.
Jincy Jose Luke R. Jordan Timothy W. Johnson Si Hoon Lee Nathan J. Wittenberg Sang‐Hyun Oh 《Advanced functional materials》2013,23(22):2812-2820
The ability to precisely control the topography, roughness, and chemical properties of metallic nanostructures is crucial for applications in plasmonics, nanofluidics, electronics, and biosensing. Here a simple method to produce embedded nanoplasmonic devices that can generate tunable plasmonic fields on ultraflat surfaces is demonstrated. Using a template‐stripping technique, isolated metallic nanodisks and wires are embedded in optical epoxy, which is capped with a thin silica overlayer using atomic layer deposition. The top silica surface is topographically flat and laterally homogeneous, providing a uniform, high‐quality biocompatible substrate, while the nanoplasmonic architecture hidden underneath creates a tunable plasmonic landscape for optical imaging and sensing. The localized surface plasmon resonance of gold nanodisks embedded underneath flat silica films is used for real‐time kinetic sensing of the formation of a supported lipid bilayer and subsequent receptor‐ligand binding. Gold nanodisks can also be embedded in elastomeric materials, which can be peeled off the substrate to create flexible plasmonic membranes that conform to non‐planar surfaces. 相似文献
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17.
Bhaskar Singh Mohammed M. Shabat Daniel M. Schaadt 《Progress in Photovoltaics: Research and Applications》2020,28(7):682-690
The photon density in solar cells is usually optimized through tailored antireflection coatings (ARCs). We develop an analytical model to describe metal hybrid nanoparticles (NPs)‐based ARC, where metal NPs are embedded in a standard ARC on a Si‐substrate. A point dipole approach is implemented to calculate diffuse reflectance by NPs, while transfer matrix method is used for specular reflectance from front surface. We found that embedding metal NPs in SiN ARC enhances the antireflection property of the former at non‐normal angles of incidence (AOI) of light. Electric field distribution patterns of radiation in the substrate by NPs are calculated for various AOI, which support the improvements in the antireflection property. Weighted solar power transmittances from ARCs are calculated, which show that Ag‐NPs (radius = 35 nm) embedded in SiN (thickness = 70 nm) performs better than SiN for AOI over 74°, whereas Al‐NPs (radius = 35 nm) embedded in SiN (thickness = 70 nm) performs better for AOI over 78°. 相似文献
18.
Dominik Hühn Alexander Govorov Pilar Rivera Gil Wolfgang J. Parak 《Advanced functional materials》2012,22(2):294-303
Agglomerated gold nanoparticle clusters embedded in polyelectrolyte films are optically excited, which results in local ablation of material from the polyelectrolyte films and in some cases leads to the formation of a gas bubble. Evidence is given that this process is mediated by superheating of the medium around the excited gold nanoparticle clusters. This process is highly dependent on the medium used. Besides the boiling point, salt and proteins in the medium also affect the formation of gas bubbles. These data demonstrate that the type of medium must be considered when describing light‐mediated heating of gold nanoparticle clusters, which are fixed in a matrix surrounded by medium. 相似文献
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20.
Zhifeng Shi Ying Li Sen Li Xinjian Li Di Wu Tingting Xu Yongtao Tian Yongsheng Chen Yuantao Zhang Baolin Zhang Chongxin Shan Guotong Du 《Advanced functional materials》2018,28(20)
This work presents a strategy of combining the concepts of localized surface plasmons (LSPs) and core/shell nanostructure configuration in a single perovskite light‐emitting diode (PeLED) to addresses simultaneously the emission efficiency and stability issues facing current PeLEDs' challenges. Wide bandgap n‐ZnO nanowires and p‐NiO are employed as the carrier injectors, and also the bottom/upper protection layers to construct coaxial core/shell heterostructured CsPbBr3 quantum dots LEDs. Through embedding plasmonic Au nanoparticles into the device and thickness optimization of the MgZnO spacer layer, an emission enhancement ratio of 1.55 is achieved. The best‐performing plasmonic PeLED reaches up a luminance of 10 206 cd m?2, an external quantum efficiency of ≈4.626%, and a current efficiency of 8.736 cd A?1. The underlying mechanisms for electroluminescence enhancement are associated with the increased spontaneous emission rate and improved internal quantum efficiency induced by exciton–LSP coupling. More importantly, the proposed PeLEDs, even without encapsulation, present a substantially improved operation stability against water and oxygen degradation (30‐day storage in air ambient, 85% humidity) compared with any previous reports. It is believed that the experimental results obtained will provide an effective strategy to enhance the performance of PeLEDs, which may push forward the application of such kind of LEDs. 相似文献