共查询到20条相似文献,搜索用时 23 毫秒
1.
利用简单的化学气相沉积方法在低温下高产量地合成了ZnO纳米带, 并利用磁控溅射对样品进行表面修饰, 制备了Au-ZnO复合纳米带. 通过扫描电镜、透射电镜及微区拉曼等手段系统地研究了表面修饰对ZnO 纳米材料发光性能的影响.结果表明, 在ZnO纳米带上溅射Au纳米颗粒, 可有效增强其近带边发光并使可见发光强度发生淬灭, 从而增强ZnO纳米带的发光性能. ZnO纳米带发光增强因子η最大可达到85倍. 基于Au纳米颗粒的散射、吸收、Purcell增强因子, 以及Ostwald熟化理论, 又进一步探讨了Au-ZnO复合材料的发光机制. 采用表面等离子体耦合的方法可以有效地提高光电半导体器件的发光效率.
关键词:
表面等离体子
光致发光
氧化锌 相似文献
2.
Jae Ik Kim Dae-Ryong Jung Jongmin Kim Changwoo Nahm Sujin Byun Sungjun Lee Byungwoo Park 《Solid State Communications》2012,152(18):1767-1770
The enhancement of surface–plasmon-coupled photoluminescence from CdS nanoparticles was examined for various thicknesses of sputtered Au films. The improved luminescence with thickness control of Au correlated well with the increased density of surface–plasmon states, which was modified by the plasmon-dispersion relation at the planar Au/PMMA interface. By annealing the Au films to form a rough surface morphology, the emission in the CdS nanoparticles was further enhanced by the improved excitation and coupling of the surface–plasmon modes. 相似文献
3.
Luminescence properties of nanocomposites consisting of ZnO nanoparticles in a conjugated polymer, poly [2-methoxy-5-(2′-ethyl hexyloxy)-phenylene vinylene] (MEH-PPV), were investigated. Photoluminescence measurements reveal a blue shift in the emission spectrum of MEH-PPV upon incorporation of ZnO nanoparticles into the polymer film while the emission is increasingly quenched with increasing ZnO concentration. In contrast, the structure of the polymer and its conjugation length are not affected by the presence of ZnO nanoparticles (up to 16 wt% ZnO) as revealed by Raman spectroscopy. The blue shift and photoluminescence quenching are explained by the separation of photogenerated electron-hole pairs at the MEH-PPV/ZnO interface and the charging of the nanoparticles. 相似文献
4.
R. R. Shamilov V. I. Nuzhdin V. F. Valeev Yu. G. Galyametdinov A. L. Stepanov 《Technical Physics》2016,61(11):1698-1703
Multilayer systems consisting of layers of hybrid quantum dots are fabricated. The quantum dots with the CdSe/CdS core/shell structure are chemically synthesized and deposited on the surface of quartz glass that contains ion-synthesized silver nanoparticles in the near-surface region. Silver nanoparticles exhibit optical absorption owing to the localized surface plasmon resonance. Variations in the photoluminescence intensity of the layer related to an increase in the distance from the quartz surface with metal nanoparticles are studied. An increase in the photoluminescence intensity is observed under excitation in the spectral region of the plasmon absorption of silver nanoparticles. An optimal distance between the layers is determined to maximize the enhancement of the photoluminescence of quantum dots in the presence of the near field of metal nanoparticles. 相似文献
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6.
Wenkai Zhang Yujie Chen Lin Gan Jian Qing Xiang Zhou Yunyun Huang Yuzhao Yang Yu Zhang Jiemei Ou Xudong Chen Ming Qiu Zhang 《Journal of Physics and Chemistry of Solids》2014
Polyfluorene-based blue light-emitting devices suffer from the shortcomings of low stability, drastic loss of quantum yield and poor color purity. To find out the solution, we use silver nanoparticles for enhancement of photoluminescence of polyfluorene copolymer (PCFOz) through localized surface plasmon resonance (LSPR) coupling effect. The photoluminescence from PCFOz can be concentrated down to nanoscale, realizing a high spatial selectivity of the fluorescence enhancement process. PL emission of conjugated polymer is blueshifted about 8 nm from the peak emission of 433 nm for the neat PCFOz film to around 425 nm for the Ag/PCFOz composite film. The full width at half maximum of PCFOz is reduced from 88 to 60 nm. Absorbance spectra and time resolved photoluminescence measurements further demonstrate that both absorption intensity and recombination rate of PCFOz increase due to strong LSPR-excitons coupling. Optical properties of such plasmon-enhanced organic light emitters were also studied by temperature-dependent PL spectroscopy from 10 to 200 K. In comparison with bare PCFOz, the LSPR induced emission enhancement ratio significantly increases with increasing temperature. These results are believed to be important for the development of highly efficient blue organic light-emitting devices based on all-solution processing. 相似文献
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Bouhelier A Bachelot R Lerondel G Kostcheev S Royer P Wiederrecht GP 《Physical review letters》2005,95(26):267405
Light emission resulting from two-photon excited gold nanoparticles has been proposed to originate from the radiative decay of surface plasmon resonances. In this vein, we investigated luminescence from individual gold nanorods and found that their emission characteristics closely resemble surface plasmon behavior. In particular, we observed spectral similarities between the scattering spectra of individual nanorods and their photoluminescence emission. We also measured a blueshift of the photoluminescence peak wavelength with decreasing aspect ratio of the nanorods as well as an optically tunable shape-dependent spectrum of the photoluminescence. The emission yield of single nanorods strongly depends on the orientation of the incident polarization consistent with the properties of surface plasmons. 相似文献
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10.
We experimentally verify that surface plasmon (SP) enhances the photoluminescence (PL) of visible light from Tb3+ -doped 60SiO2 -20Al2O3 -20CaF2 :0.3Tb 3+ , 20Yb 3+ glass ceramics by using electron beam lithography to fabricate silver nanoparticles on the surface of the glass ceramics. Numerical calculation for the SP enhancement spectroscopy is achieved by using the finite-difference time-domain algorithm. A PL enhancement of Tb3+ by as much as 1.6 times is observed. The PL enhancement is mainly due to the coupling of excitation from 7 F 6 to 5 D 4 transition dipole of Tb 3+ ion with SP mode induced from the silver nanoparticles. 相似文献
11.
纳米银与表面吸附荧光素的荧光性能的影响 总被引:2,自引:0,他引:2
研究了纳米银粒子对表面吸附荧光素(fluorescein,Fl)的荧光性能的影响。Fl溶液中加入纳米银粒子,Fl分子包覆在纳米银粒子表面形成Fln-Ag复合物使纳米银相互桥连形成类似网络的结构,且Fl分子吸收峰随着纳米银浓度的增加发生红移。纳米银通过产生的强局域场将能量传输给Fl发光中心,实现了Fl的荧光增强,荧光增强效率随着纳米银浓度的增加具有最大值。较大粒径的纳米银使Fl获得最大荧光增强效率所需浓度较低且最大荧光增强效率值较高。研究结果表明,纳米银与Fl间的能量传输主要由Fl分子附近局域电磁场增强和分子到金属表面无辐射跃迁能量转移过程所决定并与纳米银的浓度、尺寸密切相关。 相似文献
12.
C. Kennerknecht H. Hövel M. Merschdorf S. Voll W. Pfeiffer 《Applied physics. B, Lasers and optics》2001,73(4):425-429
The resonant multiple excitation of collective modes in metallic nanoparticles using ultrashort laser pulses leads to an enhanced
multiphoton photoemission from the particles. This effect is here demonstrated for the surface-plasmon resonance of Au nanoparticles
on graphite. The shape of the photoemission spectra is explained by multiphoton photo-assisted thermionic emission from the
nanoparticles and resonant emission via the image-potential state on graphite. Tuning the photon energy between 1.7 eV and
3.2 eV allows the identification of an enhancement of the photoemission yield at 2.1±0.1-eV photon energy that is attributed
to the resonant excitation of the surface plasmon in the Au nanoparticles. This identification of the surface-plasmon excitation
in this energy range is also supported by electron energy loss spectroscopy.
Received: 8 August 2001 / Revised version: 13 September 2001 / Published online: 10 October 2001 相似文献
13.
《Physics letters. A》2020,384(5):126117
An assessment of the influence of heat treatment temperature and retention time on the optical properties of a Cu+ and Sm3+ co-doped phosphate glass of interest to photonic applications is reported. Particularly, the enhancement of the orange-red photoluminescence (PL) from Sm3+ ions has been realized in the glass through the development of non-plasmonic Cu clusters. It was exposed during an in situ isothermal treatment wherein optical absorption and PL were monitored together in real time. Following the PL increase, a drop in the Sm3+ emission intensity was produced concurring with the appearance of Cu nanoparticles (NPs) exhibiting the surface plasmon resonance. Hence, the connection between energy donor (sensitizing) effects of small Cu clusters and the energy acceptor (quenching) character of Cu NPs is supported. It is the first time to the author's knowledge that the enhancement of Sm3+ luminescence via Cu clusters embedded in glass is indicated. 相似文献
14.
Zhongjian Hu 《Journal of luminescence》2010,130(5):771-20856
We report the fabrication and characterization of composite nanoparticles consisting of a conducting polymer, poly-3-hexylthiophene (P3HT), doped with varying amounts of [6,6]-phenyl C61-butyric acid methyl ester (PCBM), a material blend that is commonly applied in bulk heterojunction organic photovoltaic devices (OPVs). Single particle spectroscopy (SPS) studies, where nanoparticles are studied one particle at a time, reveal that these nanoparticles have spectroscopic characteristics consistent with the existence of two types of crystalline nanodomains, one with a higher energy emission at 660 nm and one with a lower energy emission at 720 nm. In addition, the occurrence of emission at lower peak energy increases with increasing PCBM doping levels, and the intensity of the lower energy peak emission increases with respect to the higher energy peak emission as well. These data reveal a PCBM concentration dependent formation of two types of P3HT crystalline nanodomains in P3HT/PCBM composite nanoparticles, where the lower energy crystal structure becomes more favored with higher PCBM concentration. This work provides a molecular scale insight in the correlation between changes in morphology of conjugated polymer materials with different weight percentages of fullerene dopants. 相似文献
15.
Xiuli Zhou Qiangmin Wei Lumin Wang Bhuwan Joshi Qihuo Wei Kai Sun 《Applied Physics A: Materials Science & Processing》2009,96(3):637-641
We demonstrate a method for improving photoluminescence of gallium arsenide semiconductor by simply coating a thin layer of
Au nanoparticles on its surface. Further focused ion beam bombardment at the sputter-coated Au film was conducted to control
the size, the distribution, and the morphology of the Au nanoparticles via the changes of the focused ion-beam irradiation
conditions. Photoluminescence of GaAs coated with the Au nanoparticles with average size of 5 nm in diameter is enhanced to
about threefold relative to that of pure GaAs. Numerical calculations were conducted based on finite-different time-domain
method. Results indicated that the enhancement is mainly attributed to the contribution of local surface plasmon resonance
of Au nanoparticles. 相似文献
16.
S. A. Zapunidi D. Yu. Paraschuk 《Journal of Experimental and Theoretical Physics》2008,107(6):1079-1089
A model is proposed for photoluminescence quenching due to resonant energy transfer in a blend of a conjugated polymer and a low-molecular energy acceptor. An analytical dependence of the normalized photoluminescence intensity on the acceptor concentration is derived for the case of a homogeneous blend. This dependence can be described by two fitting parameters related to the Förster radii for energy transfer between conjugated segments of the polymer and between the conjugated polymer segment and the energy acceptor. Asymptotic approximations are obtained for the model dependence that make it possible to estimate the contribution from the spatial migration of excitons to the photoluminescence quenching. The proposed model is used to analyze experimental data on the photoluminescence quenching in a blend of the soluble derivative of poly(p-phenylene vinylene) and trinitrofluorenone [13]. The Förster radius for resonant energy transfer between the characteristic conjugated segment of poly(p-phenylene vinylene) and the energy acceptor is determined to be r F = 2.6 ± 0.3 nm. 相似文献
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Ling Liu Xiaoliang Xu Tian Luo Yansong Liu Zhou Yang Jiemei Lei 《Solid State Communications》2012,152(13):1103-1107
High-quality alloyed near-infrared CdTexSe1?x quantum dots were synthesized by a modified organometallic method. The emission wavelength of the alloyed quantum dots were turned from visible to near-infrared range by changing the composition of the precursor. The photoluminescence intensity of the alloyed quantum dots was further enhanced by coupling through localized surface plasmons from Au nanoparticles. The alloyed CdTeSe quantum dots coupled with Au nanoparticles exhibited a 4 times photoluminescence enhancement than that of bare CdTeSe quantum dots by turning the localized surface plasmons resonant absorption of Au nanoparticles consistent to the excitation wavelength. This method will be beneficial for the potential applications in the biological imaging and detection. 相似文献
19.
D. Zhang A. Horneber U. Heinemeyer F. Schreiber A.J. Meixner 《Journal of luminescence》2011,131(3):502-505
In a comparison between a bare diindenoperylene (DIP) film and a DIP film spin-coated with a layer of gold nanoparticles, we have investigated the influence of plasmon resonances in the gold particles on spectroscopic properties of the molecular film. Under off-resonant excitation with a laser at 633 nm, the bare DIP film showed only weak photoluminescence (PL) and Raman signals, but after spin-coating gold nanoparticles on such a DIP film, we found an enhancement of both the PL and Raman signals by a factor of about 3, whereas no enhancement could be observed when the same sample was excited with laser light of 488 nm. This difference reveals that at 633 nm, plasmon resonances in the gold nanoparticles are excited, leading in turn to an enhancement of PL and Raman signals of the weakly absorbing DIP film via coupling between plasmons in the gold particles and exciton-polaritons in the molecular film. For the laser at 488 nm, due to a much larger absorption coefficient of DIP, excitons in the molecular film are directly excited, out-weighing the influence of an off-resonant coupling to the plasmon resonances in the gold particles occurring at much lower energy. 相似文献
20.
Surface plasmon enhanced light emission of silicon-rich silicon nitride: Dependence on metal island size 总被引:1,自引:0,他引:1
Surface plasmon coupled light emission of silicon-rich silicon nitride (SRSN) was investigated as a function of metal island size. It was found that the emission intensity was enhanced by surface plasmon (SP) and the enhancement factors increase greatly with the increase of metal island size. Moreover, SP coupled emission spectral shape was found also correlating with Ag island size. By calculating the extinction characteristics of the Ag islands, it was believed that SP scattering and absorption efficiency of the metal islands decide the photoluminescence (PL) changes including emission intensity enhancement and band position shift. 相似文献