包埋Pt纳米粒子对金属-半导体-金属结构ZnO紫外光电探测器性能的影响

利用射频磁控溅射设备制备ZnO薄膜, 最终制备ZnO/Pt纳米粒子/ZnO 结构的金属-半导体-金属型紫外光电探测器. 研究了Pt纳米粒子处在ZnO薄膜层中的不同深度对金属-半导体-金属型紫外光电探测器响应性能的影响. 结果表明, 探测器的响应度随着Pt纳米粒子在ZnO薄膜层中所处深度的增大而升高. 在60 V偏压下, 包埋Pt最深的探测器在波长365 nm处取得响应度最大值1.4 A·W^-1, 包埋有Pt探测器的响应度最大值为无Pt 纳米粒子探测器响应度最大值的7倍. 结合对ZnO薄膜表面的表征及探测器各项性能的测试, 得出包埋Pt纳米粒子增强器件的响应性能可归因于表面等离子体增强散射.     

PbS纳米晶修饰的ZnO/PVP复合电双稳器件阻变机制

采用简单旋涂工艺制备了具有ITO/PVP/ZnO NCs/PbS NCs/PVP/Al 夹心结构的有机/无机复合电双稳存储器件,与没有PbS纳米晶修饰层的器件ITO/PVP/ZnO NCs/PVP/Al相比,PbS纳米晶的引入使目标器件的开关比提高了2个数量级。结合器件的I-V曲线和能级结构分析了PbS 纳米晶修饰层对器件阻变和载流子传输的影响。结果显示,PbS纳米晶层的加入不仅优化了器件能级结构,有利于载流子的俘获和释放,还修饰了ZnO纳米晶的表面缺陷,降低了器件载流子的复合损耗。     

基于高阻ZnO薄膜的光电导型紫外探测器

本文通过射频磁控溅射法在玻璃衬底上沉积一层ZnO薄膜, 制备了Al-ZnO-Al 结构光电导型紫外探测器件, 并在室温下测试了所制备器件的暗场特性及其对紫外线的响应特性. 暗场条件下器件电流特性测试结果表明所制备的ZnO薄膜电阻率达到了3.71×10⁹ Ω · cm, 是一种高阻薄膜. 在波长365 nm, 光强303 μW/cm²的紫外线照射下, 薄膜的电阻率为7.20×10⁶ Ω · cm, 探测器明暗电流比达到了516. 40 V偏置电压条件下周期性开关紫外线照时, 探测器的上升和下降时间分别为199 ms和217 ms, 响应速度快且重复性好, 并利用ZnO半导体表面复合慢过程和体复合快过程对瞬态响应过程进行了理论拟合分析. 本文研究结果表明, 高阻ZnO薄膜紫外探测器具有良好的紫外光电响应特性.     

ZnO纳米棒的制备及紫外探测性能

通过水热法在ITO衬底上成功合成了ZnO纳米棒,并以ITO为电极制备了ZnO纳米棒紫外探测器件。在室温下测试了所制备器件对紫外光的响应性能。测试结果表明,ZnO纳米棒对紫外光有很好的光响应,在0V附近,ZnO纳米棒紫外探测器的灵敏度能达到1500。此外,通过循环测试可以观测到ZnO纳米棒紫外探测器具有良好的重复性和稳定性。     

ZnO半导体电导型X射线探测器件研究

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.     

SiO2纳米颗粒对a-AlGaN金属-半导体-金属结构紫外探测器的影响

采用对a-AlGaN表面沉积SiO₂纳米颗粒制备工艺得到了金属-半导体-金属(MSM)结构的a-AlGaN紫外探测器。与没有沉积SiO₂纳米颗粒的探测器件相比,沉积SiO₂纳米颗粒使器件的暗电流下降了一个数量级,峰值光谱响应度提高了近3个数量级,紫外/可见抑制比大于10³。     

ZnO基紫外探测器研究进展

近年来，直接带隙宽禁带半导体ZnO（3．37eV）以其优越的光电特性而成为紫外探测领域研究中的新热点。文章介绍了不同类型的ZnO基紫外光敏探测器的结构和性能，并对ZnO基紫外光敏探测器的最新研究进展和应用前景进行探讨和展望。     

6H-SiC pn结紫外光探测器的模拟与分析

运用器件模拟软件模拟了pn结6H-SiC紫外光探测器的光响应灵敏度特性.讨论了不同掺杂浓度、不同器件结深对响应灵敏度的影响.对于p+n结器件，当受光面为p+层，且厚度约为0.2μm、浓度约为9×10.18cm-3、n层浓度约为1×1 0.16cm-3时，器件有较大的响应灵敏度，R=167.2mA/W；当受光面为n+ 层 ，且厚度约为0.2μm、浓度约为9×10.18cm-3、p层浓度约为1×10.16cm-3时，器件有较大的响应灵敏度，R=183.5mA/W.通过比较可知，模型能较好地反应实际情况，与实验数据符合较好. 关键词： 6H-SiC 紫外光探测 吸收系数 光响应灵敏度     

基于小分子半导体IEICO的高性能倍增型有机光电探测器

采用溶液法制备了结构为ITO/ZnO/P3HT∶IEICO/Al和ITO/PEDOT∶PSS/P3HT∶IEICO/Al的倍增型有机光电探测器,活性层中电子给体(P3HT)和电子受体(IEICO)的质量比为100∶1。以氧化锌(ZnO)为界面层的器件在正向与反向偏压下都能良好工作,而以PEDOT∶PSS为界面层的器件只能在反向偏压下工作。-15 V偏压下,与PEDOT∶PSS界面层器件相比, ZnO界面层器件的暗电流密度(2.2μA/cm~2)降低4倍以上,1.5 mW/cm~2光照下的光电流密度(3.7 mA/cm~2)提高3倍以上,外量子效率(External quantum efficiency,EQE)平均值(3262%)、响应度平均值(13.3 A/W)和探测灵敏度平均值(1.6×10~(13) Jones)分别提高4倍、4倍和11倍以上。这些结果表明,以ZnO为倍增型有机光电探测器的界面层,可以降低器件的暗电流密度并提高器件的EQEs,从而显著提高器件的光电性能。     

ZnO纳米线紫外探测器的制备和快速响应性能的研究

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.     

Ultraviolet detectors based on ZnO films by thermal oxidation of Zn metallic films

Metallic Zn films were deposited on glass substrates by electron-beam evaporation. ZnO films were synthesized by thermal oxidation of Zn metallic films in air. At the annealing temperature of 550 °C, ZnO nanowires appeared on the surface, which mainly result from the decrease of oxidation rate. A ZnO ultraviolet photodetector was fabricated based on a metal-semiconductor-metal planar structure. The detector showed a large UV photoresponse with an increase of two orders of magnitude. It is concluded that promising UV detectors can be obtained on ZnO films by thermal oxidation of Zn metallic films. The ways of performing spectral response measurements for polycrystalline ZnO films are also discussed.      

Steps of the Giant Terahertz Photoconductance of a Tunneling Point Contact

The photoresponse of the conductance of a tunneling quantum point contact to irradiation in the frequency range of 0.5–1.7 THz has been simulated within the theory of photon-assisted tunneling. The simulation has shown that the dependences of the conductance on the Fermi energy exhibit steps corresponding to transitions with the absorption of one, two, or three photons to channels near the top of the tunnel barrier. Under experimentally achievable conditions, the ratio of the photoconductance to the dark value on these steps can reach several orders of magnitude.     

Optoelectronic characteristics of close-packed HgTe nanoparticles in the infrared range

Absorption, photoluminescence (PL), photoresponse, and I-V measurements were made for a close-packed HgTe nanoparticle film without organic capping materials to investigate its optoelectronic characteristics in the infrared (IR) range. In the absorption and PL spectra taken for the close-packed nanoparticle film, the wavelength of exciton peak was red-shifted, compared with 1-thioglycerol capped HgTe nanoparticles dispersed in solution. For the HgTe nanoparticle film, dark current was below several pA level, current was increased by about three orders of magnitude at a biased voltage of 3 V under the illumination, and photoresponse was very rapid compared with 1-thioglycerol capped HgTe nanoparticles. These optoelectronic characteristics illustrate that HgTe nanoparticles are one of promising materials for the photodetector in the IR range. Finally, the origin for the increase of photocurrent with increasing temperature observed in this study will be discussed.     

基于氧化锌纳米颗粒-石墨烯异质结构的高性能紫外光探测器 (cited: 5)

报道了一种基于水热反应制备无表面活性剂的氧化锌纳米颗粒-还原石墨烯异质结构的新方法. 研究表明异质结构中氧化锌纳米晶体颗粒的平均直径为5 nm,这些颗粒均匀分布在还原石墨烯表面,其密度可以通过反应物的浓度进行有效调节. 并进一步构建了基于这种异质结构的光电探测器. 该探测器对紫外光的响应很快,光电流响应变化可达四个量级. 这些结果表明该异质结构特别适合作为替代材料用于设计和构建高性能的紫外光探测器件.     

Thermal annealing effects on the dynamic photoresponse properties of Al-doped ZnO nanowires network

In this study, UV photodetectors based on a network of aluminium-doped zinc oxide (AZO) nanowires were manufactured at a low cost; for this purpose, a fast and simple fabrication process that involved dropping nanowires dispersion solution was employed instead of the conventional e-beam lithography process that is used to manufacture single nanowire–based UV photodetectors. It was demonstrated that nanowire network–based UV photodetectors provide a much faster UV photoresponse than conventional single nanowire–based UV photodetectors. The fast UV photoresponse of the fabricated UV photodetector can be attributed to the fact that the potential barriers formed in the nanowire network junctions effectively block the flow of electrons during the process of photocurrent decay. Furthermore, the UV photoresponse under illumination by a 254 nm UV source was studied as a function of the annealing temperature of the AZO nanowires network at a bias of 5 V. The fabricated UV photodetector showed the fastest response of 2 s to UV illumination in air when the sample was annealed in air for 1 h at 300 °C.     

不同钝化结构对非极性AlGaN-MSM紫外探测器性能的提升

在r面蓝宝石衬底上,采用金属有机化学气相沉积（MOCVD）法高温生长了未掺杂非极性AlGaN半导体薄膜,在此基础上制备了金属-半导体-金属（MSM）结构的紫外探测器。系统研究了在AlGaN半导体薄膜表面分别磁控溅射SiO₂纳米颗粒与SiO₂钝化层两种钝化手段对非极性AlGaN-MSM结构的紫外探测器性能的影响。实验结果表明：磁控溅射SiO₂纳米颗粒钝化或SiO₂钝化层两种手段都能提升AlGaN-MSM结构紫外探测器性能。暗电流测试表明,SiO₂纳米颗粒和SiO₂钝化层可使器件暗电流下降1~2个数量级,达到nA量级。光谱响应测试发现,在5 V偏压下,探测器在300 nm处具有陡峭的截止边,这表明其具有很好的深紫外特性,光谱响应提高了10³倍,紫外可见抑制比高达10⁵。     

基于石墨烯-钙钛矿量子点场效应晶体管的光电探测器

以等离子增强化学气相沉积法制备的石墨烯作为导电沟道材料,将其与无机CsPbI_3钙钛矿量子点结合,设计并制备了石墨烯-钙钛矿量子点场效应晶体管光电探测器.研究和分析了石墨烯作为场效应晶体管的电学特性及其与钙钛矿量子点结合作为光电探测器的光电特性.结果表明,石墨烯在场效应晶体管中表现出良好的电学性质,其与钙钛矿量子点的结合对波长为400 nm的光辐射具有明显的光响应,在光强为12μW时器件光生电流最大为64μA,响应率达6.4 A·W~(-1),对应的光电导增益和探测率分别为3.7×10~4,6×10~7Jones(1 Jones=1 cm·Hz~(1/2)·W~(-1)).     

Photovoltaic currents and activity of structural defects in a ferroelectric–semiconductor TlInS<Subscript>2</Subscript>: La single crystal

This paper reports on the results of the investigation of electrically active defects in the crystal structure in a layered ferroelectric–semiconductor TlInS₂: La crystal by photoinduced current transient spectroscopy (PICTS). It has been found that there are states of the crystal that differ in the magnitude of the photoresponse varying within four orders of magnitude, which is interpreted in terms of the differences in states of the domain structure of the crystal. The specific features of the recording of thermal emission from defects in the presence of an additional contribution from the photovoltaic component of the response of the crystal to excitation with light have been discussed.     

Humidity sensor and ultraviolet photodetector based on carrier trapping effect and negative photoconductivity in graphene quantum dots

We report on the experimental realization of a graphene quantum dots(GQD)-based humidity sensor and ultraviolet(UV)photodetector. We demonstrate that the conductance of the GQD increases linearly with increasing relative humidity(RH) of the surrounding environment due to the carrier trapping effect, which forms the basis of a humidity sensor. When the sensor is operated in the dark state, the sensitivity can reach as high as 0.48 nS RH~(-1). The GQD are also found to exhibit light intensity dependent negative photoconductivity under the UV irradiation, which can be exploited for UV detection. As a result of these carrier trapping and de-trapping processes, the performance of the photodetector can be significantly improved with the increasing RH, and the photoresponsivity can reach a high value of.418.1 μA W~(-1) in the high humid state of RH=90%.     

High quantum efficiency UV detection using a‐Se based photodetector

High‐sensitivity ultraviolet (UV) photodetection has been attempted by utilizing the carrier multiplication effect in amorphous selenium. The prototype photodetector presented in this Letter showed an extremely high sensitivity to UV light, so that up to 1000 carriers are generated per incident photon. This result should lead to the development of an ultrahigh‐sensitivity photodetector that can be used for spectrometric applications covering the visible to UV region. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)