摘要
氮化铝(AlN)作为一种宽带隙半导体,具有优异的物理和化学性能,在紫外发光二极管(Light Emitting Diode,LED)领域有着广泛的应用。同样,发展较为成熟的氮化镓(GaN)在该领域也有着不可替代的作用。而高性能的器件需要有良好的外延层。AlGaN基紫外LED外延层的传统制备方法是采用金属有机化学气相沉积法(Metal Organic Chemical Vapor Deposition,MOCVD),但是由于该方法中存在着强烈的预反应和Al原子本身迁移速率慢等原因,导致外延层中出现大量缺陷,使得紫外LED器件的性能降低。此外,由于不同材料以及材料与空气的折射率存在差异,使得光难以逃逸到外界,大部分光被局域在芯片内部,从而降低光提取效率以及光强。为了提高器件的光学性能,一种新的紫外LED结构被提出,文章采用时域有限差分模拟(Finite Difference Time Domain,FDTD)软件对该外延结构的光提取效率和出光强度进行了仿真。研究发现,与传统的LED结构相比,新型紫外LED结构的横磁波(TM)光模式和横电波(TE)光模式的光提取效率分别提高了19.1%和29.3%,最大出光强度分别提高了42.78%和47.18%,对器件的光学性能有着显著的改善。另外,文章还研究了新型紫外LED外延层的结构参数对器件整体光学性能的影响,在光源、物理模型尺寸和仿真条件等因素不变的情况下,获得了光学性能最佳的结构参数。
As a wide-band gap semiconductor,Aluminum Nitride(AlN)has excellent physical and chemical properties and has been widely used in the field of Light Emitting Diode(LED).Similarly,Gallium Nitride(GaN),which is well developed,also plays an irreplaceable role in this field.High performance devices need a good epitaxial layer.The traditional preparation method of AlGaN-based ultraviolet LED(UV LED)epitaxy layer is Metal Organic Chemical Vapor Deposition(MOCVD).However,due to the strong pre-reaction and slow migration rate of Al atoms in this method,a large number of defects appear in the epitaxial layer,which reduces the performance of UV LED devices.In addition,due to the difference in the refractive index of different materials and the difference in the refractive index of materials and air,light has difficulty escaping to the outside world,and most of the light is localized in the chip,thus reducing the light extraction efficiency and light intensity.In order to improve the optical performance of the device,a new UV LED structure is proposed.In this paper,Finite Difference Time Domain(FDTD)software is used to simulate the light extraction efficiency and light intensity of the epitaxial structure.It is found that compared with the traditional LED structure,the light extraction efficiency of the new UV LED structure in transverse magnetic wave(TM)mode and transverse electric wave(TE)mode is increased by 19.1%and 29.3%,respectively,and the maximum light intensity is increased by 42.78%and 47.18%,respectively,which significantly improves the optical performance of the device.In addition,the influence of the structure parameters of the epitaxial layer of the new UV LED on the overall optical properties of the device is also studied in this paper.Under the constant conditions of light source,physical model size,simulation conditions and other factors,the optimal structural parameters of the optical performance are obtained.
作者
程权炜
郭康贤
庞海萍
CHENG Quan-wei;GUO Kang-xian;PANG Hai-ping(School of Physics and Materials Science,Guangzhou University,Guangzhou 510006,China;Ningxia Rongguang Electric Energy Saving Technology Co.,Ltd,Yinchuan 750299,China)
出处
《广州大学学报（自然科学版）》
CAS
2023年第1期63-77,共15页
Journal of Guangzhou University:Natural Science Edition
基金
广州市重点研发计划资助项目(202103030002)
宁夏回族自治区重点研发计划资助项目(2022BDE02012)。
