Ag表面等离子体四极子增强型MgZnO紫外探测器的设计制备及其特性研究

	Ag表面等离子体四极子增强型MgZnO紫外探测器的设计制备及其特性研究
	陈洪宇
学位类型	博士
导师	申德振,刘可为
	2014-07
学位授予单位	中国科学院大学
学位专业	凝聚态物理
摘要	紫外探测技术是继激光和红外探测技术之后发展起来的又一新型军民两用探测技术，目前在导弹尾焰探测、空间探测、燃烧工程、火焰探测等诸多领域发挥着巨大的作用。近年来，宽禁带半导体紫外探测器因其体积小、重量轻、工作时不需滤光片、无需制冷等优点被认为是可以取代真空光电倍增管和Si光电倍增管的第三代紫外探测器。在众多宽禁带半导体材料中，ZnO基材料具有缺陷密度低，抗辐射能力强，环境友好等诸多优点，且可通过Mg的掺杂使其光学带隙在3.37-7.78 eV范围连续可调，因此被认为是制备日盲及可见盲紫外探测器的最理想材料之一。由于高质量P型ZnO基材料的制备仍是国际难题，因此，在努力实现高效稳定的P型ZnO（MgZnO）的同时，如何提高ZnO基紫外探测器的性能逐渐成为近年来人们研究的热点。据之前的文献报道可知，金属表面等离子体技术已经广泛应用提高发光二极管、太阳能电池等光电器件的量子效率等诸多性能。由于金属表面等离极化激元与宽禁带半导体之间大的能量失配限制了金属表面等离子体技术在紫外波段的应用，因此，目前报道的金属表面等离子体技术的应用主要集中在可见和红外波段。虽然最近国际上也有一些关于金属表面等离极化激元提高紫外探测器响应度的报道，但是其内部的物理机制还不是很清晰。本论文针对上述ZnO基紫外探测器研究领域的热点和难点，开展工作如下： 1．通过时域有限差分方法（FDTD）的理论模拟结果，设计制备出了一种在紫外波段具有杂化四极子的Ag纳米结构。有文献调研可知，此种杂化四极子具有偶极活性，可与紫外光发生耦合作用，为金属表面等离子体技术的应用扩展到紫外波段提供了一种新的途径。 2．通过对上述Ag纳米团簇的四极共振频率和强度的有效调控，使MgZnO材料的近带边光致发光得到了选择性增强，表明Ag纳米团簇的表面等离极化激元杂化四极子具有偶极活性，其可以与MgZnO近带边激子进行耦合作用，为Ag表面等离子体增强型MgZnO紫外探测器的制备奠定了坚实根基。 3．在前面工作基础上，制备出了一种响应峰值位于350 nm 附近的高度波长选择性增强的MgZnO/Ag复合型紫外探测器。 4．为了进一步降低探测器的光电转化能耗，设计并制备出一种全新的非对称金属-半导体-金属（Au-MgxZn1-xO-Au）结构的自驱动式ZnO 基紫外探测器，即一种可在无外加偏压下工作的紫外探测器。此种非对称金属-半导体-金属结构具有很好的普适性，可广泛应用于ZnO 基材料以外的自驱动半导体光电探测器的制备。最后在前面所有工作的基础上，我们制备出了一种高灵敏度、低能耗、低噪声的Au-MgxZn1-xO/Ag-Au自驱动紫外探测器。
其他摘要	Following the laser detection and infrared detection technology, ultraviolet (UV) detection technology is a new kind of detection technology which played an important role in both of the military and civilian areas. It has been applicated in convert communications, ﬂame sensing, air and water puriﬁcation, and missile plume sensing, etal. As the third generation detectors, the wide band band gap seminconductor detectors with compact dimensions, low weight have been considered to replace the vacuum phototube and Si-based photomultiplier which could work without cooling system and additional light filters. Among the semiconductor family, ZnO combined with Mg, which is a tunable band gaps semiconductor which is a very promising candidate for fabricating visible (VIS) and solar-blind ultraviolet photodetectors. However, due to a big challange to realize high efficiency and steady p-type ZnO (MgZnO), many performance targets of its UV detectors were not achieved design requirement. Thus, before the breakthrough in p-type doping of ZnO based materials, how to achieve a highly effective ZnO based UV detectors is becaming a hot topic. In the previous reports, surface plasmons have been widely used to improve the efﬁciency of photoelectronic devices such as light-emitting diodes and solar cells.at visible or IR range based on the dipole resonance, which is usually appear at visible or IR range. Therefore, it limited its applications in ultraviolet regime due to a large energy separation between the metallic dipole and wide gap semiconductor. Although there are some reports on improvement in UV detector responsivity via surface plasmon, but its internal mechanism is still not very clear. Thus, based on aforementioned hotspot and difficult questions of ZnO based UV photodetectors, the following researches in this paper are carried out: 1. Based the results of the FDTD simulations, we realized Ag hybrid quadrupole resonance in the Ag nanoclusters in the UV regime experimentally. As previous report, the hybrid quadrupole with an activity as dipole could interact with UV emission directly, which provide a new way for the application of surface plasmon technology to the ultraviolet regime. 2. Realization of the strong coupling tunable hybridized quadrupole plasmons and their coupling with excitons in ZnMgO/Ag system, which may lay a solid ground for the future applications of surface plsamon enhanced photodetectors. 3. We fabricated MgxZn1−xO /Ag ultraviolet photodetectors which has a high wavelength (350 nm) selectively enhancement propertity based on the previous work. 4. Realization of Self-powered Ultraviolet photodetectors based on the asymmetry metal-semiconductor-metal (Au-MgxZn1-xO-Au) structure with the same metal Au for the first time. It is worthy of note that the asymmetry metal-semiconductor-metal structure was found to be extensively applicable in fabricating other kind of semiconductor detectors. At last, we fabricate Au-MgxZn1-xO/Ag-Au decector with high responsivity, low dark current, and low energy consumption of the photoelectric conversion properties.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/41394
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	陈洪宇. Ag表面等离子体四极子增强型MgZnO紫外探测器的设计制备及其特性研究[D]. 中国科学院大学,2014.

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