共查询到20条相似文献,搜索用时 203 毫秒
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本文制备了基于ZnO纳米线阵列和ZnO薄膜的Ag-ZnO-Ag电导型X射线探测器件,研究了它们对X射线的响应特性.薄膜器件在100 V偏置时的响应度达到0.12μC/Gy,纳米线阵列器件在50 V偏压下的响应度达到0.17μC/Gy.器件工作机理研究表明,器件的响应过程与表面氧吸附与解吸附效应有关,氧气吸附与解吸附过程使得X射线辐照下的载流子寿命大幅度增加,从而使得器件对X射线具有较高的响应度.本文研究结果表明ZnO薄膜和纳米线阵列器件在X射线剂量测量领域具有应用前景. 相似文献
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采用化学气相沉积(CVD)的方法在砷化镓基底上合成直径为20 nm左右、长约数十微米的氧化锌纳米线,然后采用热扩散的方法,将生长于砷化镓基底之上的氧化锌纳米线通过600 ℃,30 min的有氧退火处理后,获得了砷掺杂的氧化锌纳米线.将获得的掺杂后的氧化锌纳米线采用电子束曝光以及真空溅射镀膜的方法将钛/金合金作为接触电极引出,从而构建成场效应晶体管.文中研究了单根氧化锌纳米线砷掺杂前后的电学特性,证实了通过砷掺杂来获得p型的氧化锌纳米线的可行性.构建的p型砷掺杂氧化锌场效应晶体管的跨导为35 nA/V,载流
关键词:
p型ZnO纳米线
砷掺杂
场效应晶体管
光致发光 相似文献
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一维ZnO纳米结构由于具有比表面积大、室温下具有大激子结合能等特点而受到广泛关注. 但是如何实现纳米结构的器件一直是目前研究的一个挑战. 文章通过水热方法, 在玻璃衬底上实现了ZnO纳米线横向生长, 并制备出基于ZnO纳米线的金属-半导体-金属紫外探测器. 测量结果显示器件在365 nm处探测器的响应度达到5 A/W, 并且制备的探测器在空气中对紫外光照具有快速的响应, 其上升时间约4 s, 下降时间约5 s, 这与ZnO纳米线中的氧空位吸附和脱附水分子相关. 相似文献
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水浴法合成ZnO纳米线薄膜的工艺参数直接影响其表面形貌, 并使其接触角及润湿性能发生变化. 本文仿真分析了轮廓算数平均偏差、偏斜度、峭度、相关长度等特征参数对随机粗糙表面特性的影响规律; 改变生长时间、种子层溶液和生长液的浓度, 批量制备了表面形貌不同的ZnO纳米线薄膜; 提出了取样长度的确定方法, 并基于扫描电镜图像和Matlab图像处理算子对ZnO纳米线薄膜表面形貌的特征参数进行了提取; 将表面形貌高度和水平方向的特征参数引入Wenzel模型, 分析了合成参数、表面形貌特征参数与接触角的影响关系. 结果表明, 合成参数变化时, 选择取样长度5.0 μm为宜; 生长液浓度大于0.125 mol/L时, ZnO纳米线之间发生重结晶, 并呈现疏水性; 改变种子层溶液浓度和生长时间, 均得到超亲水表面. 上述结论可用于不同氧化酶、细胞等在ZnO纳米线薄膜上的有效吸附及相应传感器测试性能的进一步提高.
关键词:
ZnO纳米线
水浴合成
表面形貌
接触角 相似文献
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制备了基于单根ZnO纳米线的紫外光探测原型器件,并研究了聚苯乙烯硫酸钠表面修饰对器件紫外响应特性的影响.研究发现,在相同的紫外光照射条件下,表面修饰后的器件对紫外光的探测灵敏度比修饰前提高了3个数量级.I-V特性研究表明,修饰前后器件在光照时的电导没有明显变化,但修饰后器件的暗电导却下降了3个数量级.这说明通过表面修饰降低探测器的暗电导是提高紫外光探测器灵敏度的一条重要途径.
关键词:
紫外光探测器
纳米结构
ZnO
表面修饰 相似文献
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柔性有机非易失性场效应晶体管存储器具有柔性、质轻、成本低、可低温及大面积加工等优点,在射频识别标签、柔性存储、柔性集成电路和大面积柔性显示等领域展现出巨大的应用前景.本文在介绍柔性有机非易失性场效应晶体管存储器的衬底材料、器件结构和性能参数的基础上,总结了柔性有机非易失性场效应晶体管存储器的分类,并讨论了机械应力和不同温度对柔性有机非易失性场效应晶体管存储器性能参数的影响,最后展望了柔性有机非易失性场效应晶体管存储器的应用前景以及所面临的挑战. 相似文献
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Characterization of ZnO nanowire field-effect transistors and exposed to ultraviolet radiation 下载免费PDF全文
A ZnO nanowire (NW) field-effect transistor (FET) is
fabricated and characterized, and its characterization of
ultraviolet radiation is also investigated. On the one hand, when
the radiation time is 5~min, the radiation intensity increases
to 5.1~μ W/cm2, while the saturation drain current (I_\rm
dss) of the nanowire FET decreases sharply from 560 to 320~nA. The
field effect mobility (μ ) of the ZnO nanowire FET drops from
50.17 to 23.82~cm2/(V.s) at V_\rm DS=2.5~V, and
the channel resistivity of the FET increases by a factor of 2. On
the other hand, when the radiation intensity is 2.5~μ W/cm^2
, the DC performance of the FET does not change significantly with
irradiation time (its performances at irradiation times of 5 and
20~min are almost the same); in particular, the I_\rm dss of NW FET
only reduces by about 50~nA. Research is underway to reveal the intrinsic
properties of suspended ZnO nanowires and to explore their device
applications. 相似文献
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A. A. Pronin V. I. Torgashev A. A. Bush B. P. Gorshunov A. A. Volkov A. S. Prokhorov 《Physics of the Solid State》2009,51(3):498-502
Broad-range measurements of the dynamic response of polycrystalline samples of the (Bi,Sr)FeO3?x perovskite-like solid solution are performed over a frequency range from 10 Hz to 1 GHz at temperatures of 100–300 K for the first time. The colossal dielectric constant effect and the influence of electric contacts on the results of measurements are considered. It is shown that the frequency dependences of the permittivity and dynamic conductivity of (Bi,Sr)FeO3?x samples can be described within the universal dielectric response model. 相似文献
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Z.P. Shan S.M. Zhu W. Liu K. Tang H. Chen J.G. Liu Y.D. Zheng 《Applied Surface Science》2008,254(21):6962-6966
N-doped p-type ZnO (p ∼ 1018cm-3) was grown on sapphire(0 0 0 1) substrate by metal-organic chemical vapor deposition method. Ni/Au metal was evaporated on the ZnO film to form contacts. As-deposited contacts were rectifying while ohmic behavior was achieved after thermally annealing the contacts in nitrogen environment. Specific contact resistance was determined by circular transmission line method and a minimum specific contact resistance of 8 × 10−4 Ω cm2 was obtained for the sample annealed at 650 °C for 30 s. However, Hall effect measurements indicate that, as the rapid thermal annealing temperature increased up to 550 °C or higher the samples’ conductive type have changed from p-type to n-type, which may be due to the instability nature of the present-day p-type N-doped ZnO or the dissociation of ZnO caused by annealing process in N2 ambient. Evolution of the sample's electric characteristics and the increment of metal/semiconductor interface states induced by rapid thermal annealing process are supposed to be responsible for the improvement of electrical properties of Au/Ni/ZnO. 相似文献
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《Current Applied Physics》2018,18(7):843-846
We grow atomically thin molybdenum ditelluride (MoTe2) films on a SiO2/Si substrate by means of metal–organic chemical vapor deposition (MOCVD). Our Raman spectroscopy measurements reveal the formation of 2H-phase MoTe2 films. Further, transmission electron microscopy and X-ray photoelectron spectroscopy studies indicate a three-atomic-layer structure and the surface element composition of MoTe2 films. In this study, we mainly focus on the influence of metal contacts attached to the films on their electrical performance. We fabricate 2H-phase-MoTe2-based field-effect transistors (FETs) with various metal contacts such as titanium/gold, nickel and palladium, which present p-type semiconductor properties. We also examine the influence of the work functions of the contact metals on the electrical properties of three-atomic-layer-MoTe2-based FET devices. For a p-type MoTe2 semiconductor, higher work functions of the contact metals afford narrower Schottky barrier heights (SBHs) and eventually highly efficient carrier injection through the contacts. 相似文献
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Cerium phosphate nanomaterials with different morphologies and sizes were synthesized via a hydrothermal process at 150 °C using cetyl-trimethyl-ammonium-bromide and ethylene-diamine-tetra acid as surfactants. The obtained samples were characterized by X-ray diffraction and a scanning electron microscope. A possible growth mechanism was proposed to reveal the formation process. The structural properties and the electrical conductivities of CePO4 nanomaterials were studied. The activation energies were obtained from Arrhenius plots where E a?=?1.06 eV. The ac conductivity at different temperatures for CePO4 nanomaterials showed frequency independence in the lower frequency range. The dielectric measurements were carried out as a function of frequency and temperature. Variation of the dielectric properties and the ac conductivity with frequency revealed that the dispersion is due to a Maxwell-Wagner type of interfacial polarization in general. 相似文献
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《Current Applied Physics》2020,20(1):172-177
Doping is a widely-implemented strategy for enhancing the inherent electrical properties of metal oxide charge transport layers in photovoltaic devices because higher conductivity of electron transport layer (ETL) can increment the photocurrent by reducing the series resistance. To improve the conductivity of ETL, in this study we doped the ZnO layer with aluminum (Al), then investigated the influence of AZO on the performance of inverted bulk heterojunction (BHJ) polymer solar cells based on poly [[4,8-bis [(2-ethylhexyl)oxy]benzo [1,2-b:4,5-b’]dithiophene-2,6-diyl]-[3-fluoro-2[(2-ethylhexyl)-carbonyl]-thieno-[3,4-b]thiophenediyl ]] (PTB7):[6,6]-phenyl C71 butyric acid methyl ester (PC71BM). The measured conductivity of AZO was ~10−3 S/cm, which was two orders of magnitude higher than that of intrinsic ZnO (~10−5 S/cm). By decreasing the series resistance (Rs) in a device with an AZO layer, the short circuit current (Jsc) increased significantly from 15.663 mA/cm2 to 17.040 mA/cm2. As a result, the device with AZO exhibited an enhanced power conversion efficiency (PCE) of 8.984%. 相似文献
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Polymer nanocomposite electrolytes (PNCEs) of poly(ethylene oxide) and sodium perchlorate monohydrate complexes with montmorillonite
(MMT) clay up to 20 wt.% MMT concentration of poly(ethylene oxide) (PEO) are synthesized by melt compounding technique at
melting temperature of PEO (∼70 °C) and NaClO4 monohydrate (∼140 °C). Complex dielectric function, electric modulus, alternating current (ac) electrical conductivity, and
impedance properties of these PNCEs films are investigated in the frequency range 20 Hz to 1 MHz at ambient temperature. The
direct current conductivity of these materials was determined by fitting the frequency-dependent ac conductivity spectra to
the Jonscher power law. The PNCEs films synthesized at melting temperature of NaClO4 monohydrate have conductivity values lower than that of synthesized at PEO melting temperature. The complex impedance plane
plots of these PNCEs films have a semicircular arc in upper frequency region corresponding to the bulk material properties
and are followed by a spike in the lower frequency range owing to the electrode polarization phenomena. Relaxation times of
electrode polarization and ionic conduction relaxation processes are determined from the frequency values corresponding to
peaks in loss tangent and electric modulus loss spectra, respectively. A correlation is observed between the ionic conductivity
and dielectric relaxation processes in the investigated PNCEs materials of varying MMT clay concentration. The scaled ac conductivity
spectra of these PNCEs materials also obey the ac universality law. 相似文献
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Recent progress on integrating two-dimensional materials with ferroelectrics for memory devices and photodetectors 下载免费PDF全文
Two-dimensional(2D) materials, such as graphene and Mo S2 related transition metal dichalcogenides(TMDC), have attracted much attention for their potential applications. Ferroelectrics, one of the special and traditional dielectric materials,possess a spontaneous electric polarization that can be reversed by the application of an external electric field. In recent years, a new type of device, combining 2D materials with ferroelectrics, has been fabricated. Many novel devices have been fabricated, such as low power consumption memory devices, highly sensitive photo-transistors, etc. using this technique of hybrid systems incorporating ferroelectrics and 2D materials. This paper reviews two types of devices based on field effect transistor(FET) structures with ferroelectric gate dielectric construction(termed Fe FET). One type of device is for logic applications, such as a graphene and TMDC Fe FET for fabricating memory units. Another device is for optoelectric applications, such as high performance phototransistors using a graphene p-n junction. Finally, we discuss the prospects for future applications of 2D material Fe FET. 相似文献