一维ZnO纳米复合材料制备与紫外探测器研究

发布时间：2018-03-06 03:03

本文选题：ZnO　切入点：top-down　出处：《中国科学院长春光学精密机械与物理研究所》2017年博士论文　论文类型：学位论文

【摘要】：当材料被冠以纳米的前缀时,其性质就发生了巨大的变化。上个世纪九十年代时,一批以纳米科学和纳米材料技术等为代表的新兴分支学科兴起。直到1991年由Iijima教授发现了碳纳米管,一些一维的或是准一维纳米结构,包括纳米线,纳米管,纳米棒以及纳米带由于其独特的光学,电学性质逐步应用到诸如纳米电子学,光催化,LED,化学生物传感等新生的应用中。它们具有传统体材料不具备的多种优势均与其纳米尺度特征相关联。随着特征尺度的减小,纳米材料的比表面积变大,化学活性显着增强,量子尺寸效应越发明显。ZnO纳米材料为代表的II-VI族宽禁带半导体材料是其中较为典型的例子。Zn O纳米材料具有直接带隙结构和60 meV的激子束缚能,并且具有高度可控的丰富纳米形貌,这些特性都有利于实现纳米级光电、传感等集成器件。业界一般利用紫外光刻和EBL为代表的top-down技术构建纳米器件,该类型技术效费比较低而且难以获得10纳米以下集成器件,同时缺乏面向多元应用的光电子综合集成能力。本文关注于发掘低维纳米材料的物理特性,拓展材料体系,合成形貌、尺寸可控的ZnO纳米复合材料;以bottom-up图景为主要研究线索,探索组装低维纳米材料的新方法,进而实现低成本、性能可控的纳米级光电器件。本文中取得的主要研究进展有以下四个方面的内容:1.利用电场辅助组装技术,构建基于Zn O纳米线与Ag纳米颗粒复合结构的双肖特基结可见盲紫外探测器。该器件利用较小粒径Ag纳米颗粒位于356 nm的四级偶极子表面等离子共振偶合效应获得了理想的器件性能。在5 V偏压下,器件的响应度和光电导增益为4.91×106A/W和1.67×107。2.利用化学气相传输技术在包括硅衬底,铝箔等多种材料上合成了ZnO纳米管,纳米线/纳米管,纳米棒/纳米管等多种的纳米复合结构材料,其分级结构均利用一步生长法完成,有效克服了采用分步生长法的过程中材料组分控制问题,同时提升了实验效率。3.在单片衬底上,一步合成出PL发光光谱连续可调的由ZnO纳米管作为主干与纳米线作为分枝的3D混合结构纳米材料,其调控范围为从带边蓝紫光发射主导逐步变化为深能级缺陷绿光发射为主。更为有趣的是,该衬底上的纳米结构存在与其合成形貌密切相关的可调节超疏水性。4.对于实验中合成的ZnO 3D hybrid纳米材料进行瞬态吸收和瞬态荧光发射谱的测试,发现分支结构界面处存在超快的光生载流子分离过程,进而证实了特定纳米复合结构可以有效调控材料中的电荷输运和光发射过程。这种新型3D混合结构有望应用于在光伏器件,光催化等领域。
[Abstract]:When the material is prefixed with nanometers, its properties change dramatically. In -10s, Until 1991, Professor Iijima discovered carbon nanotubes, some one-dimensional or quasi-one-dimensional nanostructures, including nanowires, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, nanotubes, and nanotubes. Nanorods and nanobelts, due to their unique optical and electrical properties, have been gradually applied to nanoscale electronics, In new applications, such as photocatalytic LED, chemical biosensor and so on, many advantages that they do not have in traditional bulk materials are related to their nanoscale characteristics. With the decrease of characteristic scale, the specific surface area of nanomaterials becomes larger. The chemical activity is significantly enhanced. The quantum size effect is becoming more obvious. The II-VI family wide band gap semiconductor material represented by ZnO nanomaterials is a typical example. ZnO nanomaterials have direct band gap structure and exciton binding energy of 60 meV. And has a highly controllable rich nano-morphology, these characteristics are conducive to the realization of nano-optoelectronic, sensing and other integrated devices. Industry generally use UV lithography and EBL as the representative of top-down technology to build nano-devices, The technology cost of this type is relatively low and it is difficult to obtain less than 10 nanometre integrated devices. At the same time, there is a lack of optoelectronic integration ability for multi-dimensional applications. This paper focuses on exploring the physical properties of low-dimensional nanomaterials and expanding the material systems. ZnO nanocomposites with controllable morphology and size were synthesized, and a new method of assembling low-dimensional nano-materials was explored based on bottom-up images, and the low cost was realized. Nanoscale optoelectronic devices with controllable performance. The main research progress in this paper includes the following four aspects: 1.The use of electric field assisted assembly technology, A double Schottky junction blind ultraviolet detector based on composite structure of ZnO nanowires and Ag nanoparticles was constructed. The coupling effect of surface plasmon resonance on the surface of quaternary dipole with smaller Ag nanoparticles at 356 nm was used in the device. Ideal device performance. At 5 V bias, The responsivity and photoconductivity gain of the device are 4.91 脳 106A / W and 1.67 脳 107.2. ZnO nanotubes, nanowires / nanotubes, nanorods / nanotubes and many other nanocomposite materials, including silicon substrates, aluminum foil and so on, have been synthesized by chemical vapor transport technology. The hierarchical structure is completed by one-step growth method, which effectively overcomes the problem of material component control in the process of adopting the stepwise growth method, and improves the experimental efficiency .3. on a monolithic substrate, Three-dimensional hybrid nanomaterials with ZnO nanotubes as trunk and nanowires as branching have been synthesized by one step with continuously tunable PL luminescence spectra. The range of regulation is from the dominant blue purple light emission to the green light emission with deep level defects. What is more interesting is that, The nanostructures on the substrate have adjustable superhydrophobicity. 4. The transient absorption and transient fluorescence emission spectra of the ZnO 3D hybrid nanomaterials synthesized in the experiment are measured. It is found that there is an ultrafast photo-carrier separation process at the interface of the branched structure. This new 3D hybrid structure is expected to be used in photovoltaic devices, photocatalysis and other fields.
【学位授予单位】：中国科学院长春光学精密机械与物理研究所
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN23;TB33

【相似文献】