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题名	氧化锌微纳米结构的制备及新型光电器件的研制
作者	王登魁
学位类别	博士
答辩日期	2015-05
授予单位	中国科学院大学
导师	赵东旭
关键词	氧化锌 微纳米结构 发光二极管 氮等离子处理 紫外探测器
其他题名	The Preparation of ZnO Micro/Nano Structures andFabrication of ZnO Photoelectric Devices
学位专业	凝聚态物理
中文摘要	ZnO是用来制作高效紫外光电器件最具发展潜力的材料，在发光二极管、激光二极管和紫外探测器等领域有广泛的应用。作为重要的直接带隙半导体，其禁带宽度为3.37eV，室温下自由激子束缚能是60meV，远高于GaN的25meV和ZnS的38meV，也远高于室温热离化能(26meV)，使得激子在室温条件下就可以发生复合发光。与其他宽禁带半导体材料相比，ZnO更有利于制作紫外光电器件。并且ZnO具有多种微纳米结构，这些微纳米器件也表现出优异的光电性能。目前，ZnO 的研究已取得了一定的进展，但仍存在一些问题亟待解决，比如：异质结发光中心通常在p-GaN与ZnO界面；带边发光红移；同质结制作困难等。本论文针对ZnO研究中存在的问题，制备了ZnO微纳米结构并制作了微纳米结构的光电器件。开展了如下创新性的工作： 1. 在ITO电极上采用溶胶凝胶的方法制备了直径为5nm的ZnO量子点，采用ZnO量子点作为发光层，p-GaN作为空穴注入层，制作了ZnO量子点/p-GaN异质结发光二极管。利用量子点的陷阱控制的空间电荷限制电流的行为，使发光二极管的发光中心集中在量子点层，得到了纯紫外发光的ZnO发光二极管，发光波长在382nm，半峰宽较窄。与先前报道的器件相比，ZnO量子点发光二极管具有高的发光强度和好的单色性。 2. 采用化学气相沉积的方法生长了高效绿色发光的ZnO微米线。ZnO微米线与p-GaN构成的异质结，在p-GaN端加正向电压时得到波长为395nm的紫外发光，在ZnO 端加正向电压时得到发光峰位于450-700nm的橙色发光。与n-GaN构成的异质结，在ZnO端加正向电压时得到波长为490nm的绿色发光。并分别详细的阐述了各种颜色发光的机理。 3. 采用氮等离子体处理的方法得到了氮掺杂的ZnO单晶。低温光致发光光谱中观察到受主束缚激子相关的发光，形成了NO受主能级，拉曼散射光谱中发现氧晶格的振动模式发生蓝移，处理后ZnO表面功函数变大，费米能级向价带移动，表明空穴浓度增加。这些结果都证明氮原子已经掺杂到ZnO晶格中。通过构造ZnO基同质结器件，得到了良好的I-V整流特性，表明获得了p型导电的N掺杂ZnO。 4. 采用磁控溅射和金属离子溅射的方法制备了Ag纳米颗粒修饰的ZnO薄膜紫外探测器。ZnO/Ag纳米颗粒/ZnO夹层结构在385nm到356nm表现出强的吸收增强，Ag纳米颗粒改善了ZnO薄膜的性能。Ag修饰的ZnO薄膜紫外探测器响应度提高了一个数量级，紫外可见抑制比提高了一个多量级。上升和下降时间明显减少。
英文摘要	ZnO has always been considered as a potential material for highly efficient ultraviolet optoelectronic devices and has many applications such as light-emitting diodes, laser diodes and ultraviolet photodetectors. ZnO has a direct wide bandgap with 3.37 eV. Compared with GaN (25 meV) and ZnS (38 meV), it has a larger exciton binding energy of 60 meV, which is far higher than the thermal energy. This can lead to exciton recombination emission at room temperature. Therefore, ZnO is more suitable for ultraviolet optoelectronics than other wide-band gap semiconductors. Moreover, ZnO has a variety of micro/nano structures, which exhibit different optical characteristics. However，The electroluminescence of the ZnO/p-GaN heterojunction LEDs emits mainly from the interface between ZnO and GaN and the red-shift of ZnO near band edge emission are often found in the devices. In our work, we prepared ZnO micro/nano structures and fabricated ZnO nano/micro photoelectric devices according to the problem of the research on ZnO. The innovative research works of this article are: 1. ZnO quantum dots with the diameter of 5 nm were fabricated on ITO glass by using a simple spin-coating method. ZnO quantum dots/p-GaN heterojunction ultraviolet light-emitting diodes were made by using ZnO quantum dots as the emission layer and p-GaN as the hole injection layer. The quantum confinement effect of QDs led the LED to emit light mainly from the QDs layer. As the result, a LED with pure ultraviolet electroluminescence has been achieved. The emission peak was located at 382nm and the full width at half maximum was narrow. Compared with the other devices, ZnO quantum dots/p-GaN has excellent characteristics of high intensity and good monochromaticity. 2. ZnO microwire clusters with great green emission had been fabricated by chemical vapor deposition method. Heterojunction light emitting diodes were prepared based on ZnO microwires and p-GaN. When the forward bias was applied on p-GaN, ultraviolet emission with 395nm was obtained. When the forward was applied on ZnO, orange emission from 450nm to 700nm was observed. Heterojunction light emitting diodes were prepared based on ZnO microwires and n-GaN. When forward was applied on ZnO, green emission located at 490nm was obtained. At last, we discussed the mechanism of electroluminescence. 3. We carried out a new method to realize the nitrogen doping of ZnO single crystal by N-plasma treatment. The acceptor-related bound exciton (A0X) emission was observed in the low temperature photoluminescence. The NO acceptor level was formed. We found the vibrational mode of oxygen lattice shift to the large wave number from Raman scattering spectra. The surface work function of ZnO with nitrogen plasma treatment became larger, the Fermi level moved to valence band, the hole concentration increased. It could be confirmed that the N atom was successfully doped into ZnO. The doping mechanism was discussed. We constructed a ZnO-based homojunction device, which I-V curve displayed perfect rectification performance. This indicated that the p-ZnO with nitrogen doped was obtained. 4. We had fabricated Ag nanoparticles modified ZnO film based UV photodetector by magnetron sputtering and metal ion sputtering method. The ZnO/Ag NPs/ZnO sandwich structure presented an absorbance gain from 385nm to 356nm and a blue shift of photoluminescence. It was demonstrated that Ag nanoparticles improved the performance of the ZnO films. The photo responsivity of Ag modified ZnO film photodetector increased one order of magnitude and the rise and fall time significantly reduced.
公开日期	2015-12-24
内容类型	学位论文
源URL	[http://ir.ciomp.ac.cn/handle/181722/48904]
专题	长春光学精密机械与物理研究所_中科院长春光机所知识产出
推荐引用方式 GB/T 7714	王登魁. 氧化锌微纳米结构的制备及新型光电器件的研制[D]. 中国科学院大学. 2015.

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