锂氮共掺杂p型氧化锌基薄膜制备及其光电器件研究

发布时间：2018-05-24 05:45

本文选题：氧化锌 + p型掺杂　；参考：《中国科学院研究生院(长春光学精密机械与物理研究所)》2015年博士论文

【摘要】：氧化锌(ZnO)是直接带隙宽禁带II-VI族化合物半导体,禁带宽度3.37 eV。由于其大的激子结合能(60 meV)和优异的光电特性,使得ZnO基材料在紫外发光器件和低阂值激光器件等方面具有巨大的应用潜力。然而ZnO p型掺杂问题还没有完全解决,其器件性能依然低下,是制约ZnO基材料在光电领域应用的瓶颈问题。本论文针对该问题展开研究,取得的主要结果如下：1.提出利用分布布拉格反射镜提高氧化锌基发光器件的性能：利用等离子体辅助分子束外延技术,采用锂氮共掺杂方法制备p型氧化锌基薄膜,构建p-MgZnO/i-ZnO/n-MgZnO双异质结发光器件。在正向电压下,获得了室温下发光峰位于400 nm附近的电致发光,发光来源于ZnO近带边发光。在器件背侧加入反射率在400 nm附近约为98%的分布布拉格反射镜,使器件表面发光强度提高了1.6倍。2.提出引入空穴注入层显著提高了氧化锌基发光器件的输出功率：针对p型氧化锌空穴浓度低,影响发光器件性能的问题,引入p型GaN作为空穴注入层,构建n-ZnO/p-ZnO/p-GaN发光器件。在注入电流为60 mA时,器件发光功率达到18.5μW,比无空穴注入层的ZnO p-n结提高了3个数量级,该器件性能的提高是由于空穴从p-GaN注入到p-ZnO中,并与n-ZnO中的电子复合发光。3.利用高结晶质量的氧化锌纳米线阵列作为发光层,实现了氧化锌p-n结电泵浦随机激光：利用金属有机物化学气相沉积技术,在蓝宝石衬底上生长ZnO纳米线阵列,在此基础上利用分子束外延生长p型MgZnO,构建ZnO纳米线/p-MgZnO核壳异质结器件,获得了室温下电泵浦随机激光。激光阈值电流约为15 mA。ZnO纳米线高的结晶质量以及异质结结构对载流子的限制作用,有助于降低激射阈值。由此证明,纳米线核壳异质结结构是制备电泵浦随机激光器件的良好结构。并且采用高空穴浓度的p型金刚石作为空穴注入层,提高了此器件的性能.
[Abstract]:Zinc oxide (ZnO) is a direct band gap wide band gap II-VI compound semiconductor with a band gap of 3.37 EV. Due to its large exciton binding energy (60 MEV) and excellent optoelectronic properties, ZnO based materials have great application potential in UV luminescent devices and low threshold laser devices. However, the problem of p-type ZnO doping has not been completely solved, and its device performance is still low, which is the bottleneck problem that restricts the application of ZnO based materials in the field of optoelectronics. The main results of this paper are as follows: 1. Using distributed Bragg reflector to improve the performance of ZnO-based luminescent devices, P-type ZnO thin films were prepared by using plasma assisted molecular beam epitaxy (MBE) technique and co-doped with lithium nitrogen, and p-MgZnO/i-ZnO/n-MgZnO double heterojunction light-emitting devices were constructed. At the forward voltage, the electroluminescence with a peak near 400nm is obtained at room temperature. The luminescence comes from the near-band luminescence of ZnO. A distributed Bragg reflector with a reflectivity of about 98% near 400 nm is added to the back of the device, which increases the luminescence intensity of the device surface by 1.6 times. It is proposed that the hole injection layer can significantly increase the output power of ZnO based light-emitting devices. In view of the problem that the concentration of p-type ZnO holes is low and the performance of the devices is affected, p-type GaN is introduced as the hole injection layer to construct the n-ZnO/p-ZnO/p-GaN light-emitting devices. When the injection current is 60 Ma, the luminescence power of the device reaches 18.5 渭 W, which is three orders of magnitude higher than that of the ZnO p-n junction without hole injection layer. The improvement of the device performance is due to the hole being injected from p-GaN to p-ZnO and recombined with the electron in n-ZnO. 3. Using ZnO nanowire array with high crystalline quality as the luminescent layer, an electrically pumped random laser with ZnO p-n junction was realized. ZnO nanowire arrays were grown on sapphire substrates by metal-organic chemical vapor deposition. On this basis, p-type MgZnO grown by molecular beam epitaxy (MBE) was used to fabricate ZnO nanowire / p-MgZnO core-shell heterojunction devices, and an electrically pumped random laser was obtained at room temperature. The laser threshold current is about 15 mA.ZnO nanowires with high crystallization quality and the limiting effect of heterojunction structure on carriers, which is helpful to reduce the threshold of laser emission. It is proved that nanowire core-shell heterostructure is a good structure for the fabrication of electrically pumped random laser devices. The high hole concentration p-type diamond is used as the hole injection layer to improve the performance of the device.
【学位授予单位】：中国科学院研究生院(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】：2015
【分类号】：TB383.2

【共引文献】