稳定的锂氮共掺杂p型氧化锌及其光电器件研究

	稳定的锂氮共掺杂p型氧化锌及其光电器件研究
	申赫
学位类型	博士
导师	单崇新
	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	氧化锌(ZnO)作为半导体材料，它是直接带隙的宽禁带(3.37 eV)半导体。此外，ZnO的室温激子结合能高达60 meV，这些特点使得ZnO有望实现在紫外波段的发光和探测以及低阈值激光等器件方面的应用。正因为此，ZnO近年来成为半导体光电研究领域的国际前沿和热点。经过十多年的探索，ZnO的研究取得了一系列具有里程碑意义的成果。但是，到目前为止，ZnO的p型掺杂问题还没有完全解决，稳定的p型ZnO材料还很难获得。针对ZnO发展所面临的关键性问题，本论文开展了研究，取得的主要结果如下：1. 以等离子体辅助下的分子束外延技术为主要实验手段获得了Li-N共掺杂的ZnO:(Li,N)材料薄膜，通过对薄膜的Hall测试，显示这些薄膜均为p型导电，其空穴浓度为1016 cm-3量级，且在超过200天的重复性Hall测量中，样品始终保持p型导电，通过XPS、变温PL设备对其p型机制及其稳定性原因进行了探究，并通过同步辐射光源辅助下的X射线吸收精细结构(XAFS)技术加以印证。这些结果都显示Li-N共掺杂可以实现稳定的p型ZnO。2. 在获得稳定的Li-N共掺杂p型ZnO的基础上，制备了一系列ZnO同质pn结型器件，并得到了室温电致发光。在超过半年的重复性测试中，样品的电致发光稳定性良好。为了提高ZnO同质pn结型器件的电致发光效率，利用表面等离子体可以增强发光材料及器件发光效率的原理，通过表面悬涂Ag纳米粒子实现了对ZnO同质pn结型器件电致发光强度的提高，这是对表面等离子体增强ZnO同质pn结型电致发光器件的首次报道，并且该表面等离子体增强器件在超过3个月的重复性测试中亦十分稳定，这也是第一次对表面等离子体增强器件稳定性研究的报道。3. 对同质pn结在自供能紫外探测器件方面的应用进行探究，在无外加电场作用下，对于特定紫外波段的光，该ZnO同质pn结型器件响应显著，响应的峰值出现在380 nm附近，半峰宽仅为9 nm，展现了其在自供能、高光谱选择性紫外探测器件方面的应用潜力，对其进行稳定性测试，在超过5个月的测试周期内，器件的响应谱未发现明显变化，首次实现了稳定、高光谱选择性的ZnO同质pn结型自供能紫外探测器件。
其他摘要	Znic Oxide (ZnO), as a semiconductor material, has a direct and wide band gap (3.37 eV). Moreover, the room temperature exiciton binding energy of ZnO is 60 meV. With the characters above, ZnO may achieve a wide range of applications in ultraviolet (UV) light-emitting devices (LEDs), UV detectors, low threshold lasers, etc. And for these reasons, ZnO become the international frontier and hot spot of semiconductor optoelectronic research field in recent years. After a decade of exploration, the research on ZnO has made a series of landmark achievements. But the problem in the p-type doping ZnO has not been solved completely until now. Stable p-type ZnO is still hard to obtain. The present work is focused on the key issue that hinder the development of ZnO, and the following results are obtained:1. Li-N codoped ZnO:(Li,N) films have been obtained by the plasma-assisted molecular beam epitaxy technique. The ZnO:(Li,N) films show p-type conduction as measured by Hall measurement, and the hole concentration is of the order of magnitude of 1016 cm−3. The p-type conduction can maintain for over 200 days. The formation mechanism of the p-type ZnO and why the p-type conduction can last for such a long time have also been investigated by XPS and temperature-dependent PL and supported by Synchrotron-based x-ray absorption fine structure(XAFS) technique. The results above indicating the good stability of the p-type ZnO can be obtained via the Li-N codoping method.2. On the basis of the prepared stable p-type ZnO films, some ZnO homojunction LEDs have been constructed and the electroluminescence (EL) at room temperature has been observed from the ZnO homojunction. The LEDs fabricated from the ZnO homojunctions have been measured intermittently for over half a year and show the good stability of EL. In order to increase the EL emission of ZnO homo pn junction LEDs, the Ag nanoparticles (NPs) were spin-coated onto the ZnO homojunction LEDs by using the principle that surface plasmons can be employed to increase the emission of luminescent materials and devices. And the EL emission of the ZnO homojunction LEDs can be enhanced significantly by Ag NPs. This is the first report on surface plasmon enhanced ZnO homojunction LEDs to the best of our knowledge. The surface plasmon enhanced LEDs also show the good stability after measuring intermittently for three months. Note that no report on the stability of surface plasmon enhanced devices can be found before.3. The applicability of the ZnO pn homojunction in self-powered UV photodetectors has been explored. The photoresponse spectrum of the ZnO pn homojunction devices without any external power source only shows a dominant peak at around 380 nm, whose full width at half maximum is only 9 nm. The above characters of the devices demonstrate the potential applications in self-powered highly spectrum-selective UV photodetectors. In order to evaluate the reliability of the self-powered highly spectrum-selective UV photodetectors, the response spectrum of the device without any external power source has been recorded intermittently. The response spectrum of the device degrades little after five months. Reliable self-powered highly spectrum-selective ZnO homojunction UV photodetectors have been realized for the first time.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/41460
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	申赫. 稳定的锂氮共掺杂p型氧化锌及其光电器件研究[D]. 中国科学院大学,2014.

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