QQ客服 官方微博 反馈留言

题名	锂氮共掺杂p型氧化锌基薄膜制备及其光电器件研究
作者	卢英杰
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	单崇新
关键词	氧化锌 p型掺杂 发光二极管 随机激光
其他题名	Li-N codoping of p-type ZnO based films and their applications in optoelectronic devices
学位专业	凝聚态物理
中文摘要	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阈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18.5 μW，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。
英文摘要	Zinc oxide (ZnO) has a direct wide bandgap (3.37 eV) and a large exciton binding energy (60 meV). It is a promising candidate for high-performance ultraviolet light-emitting devices (LEDs) and low threshold laser diodes. However, the reported performance of ZnO homojunction LEDs is still far below expectation. The main factor that limits the performance of ZnO homojunction LEDs lies on its poor p-type conduction of ZnO. The present work is focused on the subject of how to improve the performance of ZnO-based LEDs and random lasers. The following results have been achieved: 1. Enhanced emission from ZnO-based LEDs by a distributed Bragg reflector: Double hetero-structured n-MgZnO/i-ZnO/p-MgZnO LEDs have been fabricated and the p-type MgZnO layer was obtained via a lithium–nitrogen codoping method. Obvious emission at around 400 nm has been observed from the LEDs under forward bias. To increase the light extraction from the LEDs, a distributed Bragg reflector whose reflectivity is 98% at 400 nm was bonded on the back side of the device, and the emission of the device was enhanced by around 1.6 times with the reflector. 2. Improved performance of ZnO-based LEDs by introducing a hole-injection layer: By introducing a p-type GaN as the hole-injection layer, n-ZnO/p-ZnO/p-GaN LEDs have been fabricated. The output power of the LEDs can reach 18.5 μW when the drive current is 60 mA, which is almost three orders of magnitude larger than the pristine LEDs without the hole-injection layer. The improved performance can be attributed to the extra holes injected into the p-ZnO layer from the p-GaN hole-injection layer. 3. Electrically pumped random lasing realized in ZnO-based p-n junctions with high crystalline ZnO nanowire arrays as the active layer: Well-aligned ZnO nanowire arrays have been prepared by MOCVD technique, and p-MgZnO has been deposited by MBE technique onto the nanowires to form ZnO nanowires/p-MgZnO core-shell heterostructures. Under the injection of continuous current, random lasing with a threshold current of around 15 mA has been observed from the heterostructures. The low threshold may be due to the relatively high crystalline quality of the ZnO nanowires as well as the effective carrier confinement in the heterostructures. These results suggest that nanowire core-shell p-n heterostructures may be a promising structure for electrically pumped random lasers. The performance of the laser diode has been improved by using a p-type diamond as a hole injection layer to increase the hole injecting into the nanowires.
公开日期	2015-12-24
内容类型	学位论文
源URL	[http://ir.ciomp.ac.cn/handle/181722/48879]
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	卢英杰. 锂氮共掺杂p型氧化锌基薄膜制备及其光电器件研究[D]. 中国科学院大学. 2015.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。