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1.
用化学浴法在ZnO纳米棒表面沉积ZnS制备出ZnO/ZnS核壳纳米棒阵列,使用SEM、XRD和XPS等手段表征了样品的形貌、结构和成分。结果表明,ZnO/ZnS核壳纳米棒阵列表面粗糙,生长致密、分布均匀,其平均直径约为150 nm。以Pt为对电极组装的自供能ZnO/ZnS异质结紫外探测器,对紫外光具有很好的探测性能,能循环工作且性能稳定。这种探测器对微弱的紫外光也有较强的响应和较高的光敏性,且随着光强度的提高光电流密度线性增大。与自供能ZnO纳米棒紫外探测器相比,ZnO/ZnS异质结紫外探测器具有更高的响应速度,上升时间和下降时间分别提高到0.02 s和0.03 s。 相似文献
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Feng Teng Weixin Ouyang Yanmei Li Lingxia Zheng Xiaosheng Fang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(22)
A novel type of high performance ultraviolet (UV) photodetector (PD) based on a ZnO film has been prepared by incorporating a BiOCl nanostructure into the film. The responsivity of the BiOCl/ZnO hybrid film PD in UV region can reach 182.87 mA W?1, which is about 2.72 and 6.87 times for that of TiO2/ZnO hybrid film PD and pure ZnO film PD. The rise/decay time of BiOCl/ZnO hybrid film PD is 25.83/11.25 s, which is much shorter than that of TiO2/ZnO hybrid film PD (51.94/26.05 s) and pure ZnO film PD (69.34/>120 s). The BiOCl nanostructure can inject photogenerated electrons into the ZnO film under UV light illumination, leading to the increase of photocurrent, and forms barriers to block the straight transmission of electrons between electrodes, resulting in the decrease of decay time. The results of control experiment show that the transfer path of photogenerated electrons formed by p–n junction will be cut off after depositing gold nanoparticles on the film surface, which means this hybrid film is a unique and novel structure to improve the optoelectronic performance of photodetectors. This novel BiOCl/ZnO hybrid structure paves new route for the development of film PDs based on ZnO film. 相似文献
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Novel Transparent and Self‐Powered UV Photodetector Based on Crossed ZnO Nanofiber Array Homojunction
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Yi Ning Zhiming Zhang Feng Teng Xiaosheng Fang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(13)
A novel self‐powered UV photodetector based on electrospun ZnO nanofiber arrays is introduced. Aligned pure ZnO nanofibers and Ag‐doped p‐type ZnO nanofibers are processed perpendicular to each other, and p–n junction arrays of ZnO nanofibers are fabricated as a result. Owing to the intrinsic intervals between nanofibers, the device is fully transparent on quartz substrate. Various characterization methods including TEM, XRD, and XPS are used to testify the existence form of Ag element in ZnO nanofibers, and a field effect transistor is constructed to judge their conductivity. It is discovered that the Ag doping process not only transforms ZnO to p‐type conductivity, making it possible to build this self‐powered photodetector, but also forms Ag nanoparticles in ZnO nanofibers and thus helps reduce the response time. Benefiting from the abovementioned dual effects, this UV detector is found to have an enhanced performance, with the on–off ratio up to 104 at zero bias and a rather short rise/decay time of 3.90 s/4.71 s. 相似文献
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Ming‐Yu Li Muni Yu Dong Su Jianbing Zhang Shenglin Jiang Jiang Wu Qingping Wang Sisi Liu 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(28)
Strong near‐surface electromagnetic field formed by collective oscillation of electrons on Cu nanostructure a shows a strong dependence on geometry, offering a promising approach to boost the light absorption of ZnO photoactive layers with enhanced plasmon scattering. Here, a facile way to fabricate UV photodetectors with tunable configuration of the self‐assembled Cu nanostructures on ZnO thin films is reported. The incident lights are effectively confined in ZnO photoactive layers with the existence of the uplayer Cu nanostructures, and the interdiffusion of Cu atoms during fabrication of the Cu nanostructures can improve the carrier transfer in ZnO thin films. The optical properties of the hybrid architectures are successfully tailored over a control of the geometric evolution of the Cu nanostructures, resulting in significantly enhanced photocurrent and responsivity of 2.26 mA and 234 A W?1 under a UV light illumination of 0.62 mW cm?2 at 10 V, respectively. The photodetectors also exhibit excellent reproducibility, stability, and UV–visible rejection ratio (R370 nm/R500 nm) of ≈370, offering an approach of high‐performance UV photodetectors for practical applications. 相似文献
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Vinh Quang Dang Tran Quang Trung Do‐Il Kim Le Thai Duy Byeong‐Ung Hwang Doo‐Won Lee Bo‐Yeong Kim Le Duc Toan Nae‐Eung Lee 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(25):3054-3065
Ultraviolet (UV) photodetectors based on ZnO nanostructure/graphene (Gr) hybrid‐channel field‐effect transistors (FETs) are investigated under illumination at various incident photon intensities and wavelengths. The time‐dependent behaviors of hybrid‐channel FETs reveal a high sensitivity and selectivity toward the near‐UV region at the wavelength of 365 nm. The devices can operate at low voltage and show excellent selectivity, high responsivity (RI ), and high photoconductive gain (G). The change in the transfer characteristics of hybrid‐channel FETs under UV light illumination allows to detect both photovoltage and photocurrent. The shift of the Dirac point (V Dirac) observed during UV exposure leads to a clearer explanation of the response mechanism and carrier transport properties of Gr, and this phenomenon permits the calculation of electron concentration per UV power density transferred from ZnO nanorods and ZnO nanoparticles to Gr, which is 9 × 1010 and 4 × 1010 per mW, respectively. The maximum values of RI and G infer from the fitted curves of RI and G versus UV intensity are 3 × 105 A W?1 and 106, respectively. Therefore, the hybrid‐channel FETs studied herein can be used as UV sensing devices with high performance and low power consumption, opening up new opportunities for future optoelectronic devices. 相似文献
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F. Oliveira M.I. Vasilevskiy J. Ayres de Campos J.S. Martins E. Alves 《Thin solid films》2010,518(16):4612-4614
ZnO:Mn transparent thin films (thickness < 1 μm) with the Mn contents ranging from 1.8 to 3.25 at.% were grown by RF magnetron co-sputtering. The films are nanocrystalline, with wurtzite-structure grains of a typical size of 20 nm and with a preferential orientation of the c-axis perpendicular to the surface. According to the Raman spectroscopy data, Mn mostly substitutes Zn in the lattice sites. In spite of these factors, the nanostructure and the Mn(Zn) substitution, that are considered favorable for ferromagnetism in this material, both magnetic resonance and Faraday effect measurements show paramagnetic behavior of the ZnO:Mn films and the absence of ferromagnetic order at room temperature. 相似文献
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ZnO Film UV Photodetector with Enhanced Performance: Heterojunction with CdMoO4 Microplates and the Hot Electron Injection Effect of Au Nanoparticles
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Weixin Ouyang Feng Teng Mingming Jiang Xiaosheng Fang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(39)
A novel CdMoO4–ZnO composite film is prepared by spin‐coating CdMoO4 microplates on ZnO film and is constructed as a heterojunction photodetector (PD). With an optimized loading amount of CdMoO4 microplates, this composite film PD achieves a ≈18‐fold higher responsivity than pure ZnO film PD at 5 V bias under 350 nm (0.15 mW cm−2) UV light illumination, and its decay time shortens to half of the original value. Furthermore, Au nanoparticles are then deposited to modify the CdMoO4–ZnO composite film, and the as‐constructed photodetector with an optimized deposition time of Au nanoparticles yields an approximately two‐fold higher photocurrent under the same condition, and the decay time reduces by half. The introduced CdMoO4 microplates form type‐II heterojunctions with ZnO film and improve the photoelectric performance. The hot electrons from Au nanoparticles are injected into the CdMoO4–ZnO composite film, leading to the increased photocurrent. When the light is off, the Schottky barriers formed between Au nanoparticles and CdMoO4–ZnO composite film block the carrier transportation and accelerate the decay process of current. The study on Au‐nanoparticle‐modified CdMoO4–ZnO composite film provides a facile method to construct ZnO film based PD with novel structure and high photoelectric performance. 相似文献
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自驱动光探测器能够在无外加偏压的情况下将光信号转化为电信号, 在工业和军事领域有着广泛的应用。本研究报道了p型Se薄膜和n型ZnO纳米棒阵列异质结的可控合成以及它们作为自驱动紫外-可见光探测器的应用。由于在ZnO和Se的界面处形成的内建电场将光生电子-空穴对分离, 促使它们向相反方向传输, 最终被电极收集, 在0偏压下获得了较高的光电流(435 pA), 从而实现无线的自驱动光电探测。并且, 在Se和ZnO界面处沉积的Al2O3层有效降低了暗电流。最终, 此器件在500 nm的单色光下显示了高响应率55 μA·W -1和大比探测率5×10 10Jones, 并表现出了极快的响应速度(上升时间0.9 ms, 衰减时间0.3 ms)。 相似文献
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以二水合醋酸Zn为原料 ,采用反应沉积方法在非晶玻璃衬底上制备出了高度c轴取向、结晶良好的ZnO薄膜。研究了不同衬底温度和Zn源温度对ZnO薄膜性质的影响 ,探讨了不同衬底温度和Zn源温度下生长ZnO薄膜的最佳参数。本文还讨论了该方法制备ZnO薄膜的沉积机制及优化条件下样品的透光特性。 相似文献
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ZnO nanoparticles have received enormous attention due to their wide range of application such as diodes, ultraviolet-protection films, catalysts, sensors, ceramics and solar energy transformation parts. In the current research, ZnO nanoparticles were prepared by polymer decomposition. Synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transition electron microscopy (TEM) and size distribution of these particles was investigated. Narrow size distribution of particles with a diameter of 20–30 nm and the regular distribution of ZnO nanoparticles were attributed to the application of poly amidoxime polymer. The results show that the polymer thermal decomposition technique is a feasible method for production of ZnO nanoparticles. 相似文献
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Nanonetworks: Rapid Fabrication Technique for Interpenetrated ZnO Nanotetrapod Networks for Fast UV Sensors (Adv. Mater. 10/2014)
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Dawit Gedamu Ingo Paulowicz Sören Kaps Oleg Lupan Sebastian Wille Galina Haidarschin Yogendra Kumar Mishra Rainer Adelung 《Advanced materials (Deerfield Beach, Fla.)》2014,26(10):1473-1473
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Here, we report for the first time the fabrication of metal–semiconductor–metal ultraviolet photodetector based on catalyst-free growth of ZnO nanowire networks on ITO seeds/glass substrates by thermal evaporation method. The morphological, structural, and optical properties of the sample were studied by using field emission scanning electron microscopy, X-ray diffraction, photoluminescence, and UV–Vis spectrophotometer. Upon exposure to 365 nm light (1.5 mW/cm2) at five-bias voltage, the device showed 2.32 × 103 sensitivity. In addition, the photocurrent was 1.79 × 10−4 A, and the internal gain of the photodetector was 24.2. The response and the recovery times were calculated to be 3.9 and 2.6 s, respectively, upon illumination to a pulse UV light (365 nm, 1.5 mW/cm2) at five-bias voltage. All of these results demonstrate that this high-quality detector can be a promising candidate as a low-cost UV photodetector for commercially integrated photoelectronic applications. 相似文献
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The ZnO homojunction fabricated from undoped and 1 mol% AlN doped (codoped) ZnO targets by RF magnetron sputtering has been reported. The grown films on Si (100) substrate have been characterized by X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Photoluminescence (PL) and Hall measurements. The increase of d-space value (compared with unstressed bulk) found from XRD for AlN codoped ZnO film supports the formation of p-ZnO due to the N incorporation. The presence of N in the film has been confirmed by EDS and XPS analysis. Further, the p-conductivity in AlN codoped ZnO has been evidenced by low temperature PL (donor-acceptor-pair emission) and room temperature PL (red shift in near-band-edge emission). Hall measurement shows that 1 mol% AlN codoped ZnO has the hole concentration of 3.772 × 1019 cm−3. The fabricated homojunction with 1% AlN doped ZnO (p-type) and undoped ZnO (n-type) exhibits a typical rectification behavior with high breakdown voltage, and rectification ratio, 13.4. The junction parameters such as ideality factor, barrier height and series resistance have also been calculated for the fabricated p-n junction. The energy band diagram has been proposed for the fabricated homojunction. 相似文献
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通过电喷雾和二步热处理法制备得到无硬团聚的ZnO纳米微粒, 为制备无硬团聚氧化物纳米粉体提供了一种新方法. 试验采用添加适量PVP的Zn(CH3COO)2·2H2O的乙醇溶液作为电喷雾液体, 经过锥形喷雾得到均匀的微米级小液滴. 干燥后的喷雾产物先后在氮气炉和空气炉中分别600℃和400℃保温1h进行二步热处理. SEM、XRD测试结果表明, 使用该方法制备得到的ZnO纳米微粒粒度均匀, 结晶完整, 无硬团聚, 具有六角纤锌矿结构. 相似文献
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Seongcheol Mun Hyun Chan Kim Hyun-U Ko Lindong Zhai Jung Woong Kim 《Science and Technology of Advanced Materials》2013,14(1):437-446
AbstractThis paper reports the synthesis and UV sensing characteristics of a cellulose and ZnO hybrid nanocomposite (CEZOHN) prepared by exploiting the synergetic effects of ZnO functionality and the renewability of cellulose. Vertically aligned ZnO nanorods were grown well on a flexible cellulose film by direct ZnO seeding and hydrothermal growing processes. The ZnO nanorods have the wurtzite structure and an aspect ratio of 9 ~ 11. Photoresponse of the prepared CEZOHN was evaluated by measuring photocurrent under UV illumination. CEZOHN shows bi-directional, linear and fast photoresponse as a function of UV intensity. Electrode materials, light sources, repeatability, durability and flexibility of the prepared CEZOHN were tested and the photocurrent generation mechanism is discussed. The silver nanowire coating used for electrodes on CEZOHN is compatible with a transparent UV sensor. The prepared CEZOHN is flexible, transparent and biocompatible, and hence can be used for flexible and wearable UV sensors. 相似文献