Advantages of AlGaN Tunnel Junction in N-Polar 284 nm Ultraviolet-B Light Emitting Diode

IF 1.8 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

ECS Journal of Solid State Science and Technology Pub Date : 2024-06-10 DOI:10.1149/2162-8777/ad52c2

Hafeez Ur Rahman, Khalid. Ayub, Nawaz Sharif, M. Ajmal Khan, Fang Wang, Yuhuai. Liu

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引用次数: 0

Abstract

Smart, low cost and environmentally safe aluminum gallium nitride (AlGaN)-based ultraviolet-B light-emitting diodes (UV-B LEDs) are promising in real-world applications including medical as well as agricultural sciences. Higher efficiency droops, low hole injection efficiency, and high operating voltage are the key problems that AlGaN-based UV-B LEDs are facing. In this work, a smart and clean AlGaN-based UV-B LED at 284 nm emission wavelength has been studied. Here an approach is presented to electrically operate the quantum tunnelling probability by exploiting the transported carriers at the interface of p-AlGaN/n-AlGaN/n⁺⁺-AlGaN tunnel junction (TJ) with moderate Si and Mg-doping levels and optimized thickness with the help of simulation study. The simulation results show that the Augur recombination rate is successfully suppressed and quite a high radiative recombination rate is achieved in the 284 nm N-polar AlGaN-based TJ UV-B LEDs, which is attributed to the improved hole injection toward the MQWs when compared to C-LED (conventional-LED). It is found that C-LED has a maximum IQE (internal quantum efficiency) of 40% under 200 A cm⁻² injection current with an efficiency drop of 15%, while the TJ-LED has a maximum IQE of 93% with an efficiency droop of 0%. In addition, TJ-based AlGaN LED emitted power has been improved by 6 times compared to the C-LED structure. The emitted powers of TJ-LED increase linearly under varying current densities, whereas in the case of C-LED, the emitted power changes nonlinearly under varying current densities. This is attributed to the lower Augur recombination rate in the MQWs of N-AlGaN-based TJ UV-B LED. The operating voltages were reduced from 5.2 V to 4.1 V under 200 mA operation, which is attributed to the thickness and doping optimization in TJ and better selection of relatively lower Al-content in the contact layer. N-polar AlGaN-based TJ is explored for UV-B LEDs and the demonstrated work opens the door to epitaxial growth of high-performance UV emitters in MOCVD and MBE for a plethora of biomedical applications.

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氮化铝镓隧道结在 N 极 284 纳米紫外线-B 发光二极管中的优势

基于氮化铝镓（AlGaN）的智能、低成本和环保型紫外线-B 发光二极管（UV-B LED）在医疗和农业科学等实际应用中大有可为。更高的效率衰减、低空穴注入效率和高工作电压是氮化镓基紫外-B 发光二极管面临的关键问题。在这项工作中，我们研究了一种智能、清洁的基于氮化铝的紫外-B LED，其发射波长为 284 nm。本文提出了一种方法，利用硅和镁掺杂水平适中、厚度优化的 p-AlGaN/n-AlGaN/n++-AlGaN 隧道结 (TJ) 界面上的载流子传输，通过模拟研究对量子隧道概率进行电动操作。仿真结果表明，与 C-LED（传统 LED）相比，284 nm N 极 AlGaN 基 TJ UV-B LED 成功抑制了 Augur 重组率，并实现了相当高的辐射重组率，这归因于向 MQWs 注入空穴的效果得到了改善。研究发现，在 200 A cm-2 注入电流下，C-LED 的最大 IQE（内部量子效率）为 40%，效率下降 15%，而 TJ-LED 的最大 IQE 为 93%，效率下降 0%。此外，与 C-LED 结构相比，基于 TJ 的 AlGaN LED 发射功率提高了 6 倍。TJ-LED 的发射功率在不同电流密度下呈线性增长，而 C-LED 的发射功率在不同电流密度下呈非线性变化。这归因于基于 N-AlGaN 的 TJ UV-B LED 的 MQW 中较低的奥古重组率。在 200 mA 工作电流下，工作电压从 5.2 V 降至 4.1 V，这归功于 TJ 的厚度和掺杂优化以及接触层中相对较低的铝含量的更好选择。为紫外线-B LED 探索基于氮化铝镓的 N 极 TJ，所展示的工作为在 MOCVD 和 MBE 中外延生长高性能紫外线发射器打开了大门，可用于大量生物医学应用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

ECS Journal of Solid State Science and Technology MATERIALS SCIENCE, MULTIDISCIPLINARY-PHYSICS, APPLIED

CiteScore

4.50

自引率

13.60%

发文量

455

期刊介绍： The ECS Journal of Solid State Science and Technology (JSS) was launched in 2012, and publishes outstanding research covering fundamental and applied areas of solid state science and technology, including experimental and theoretical aspects of the chemistry and physics of materials and devices. JSS has five topical interest areas: carbon nanostructures and devices dielectric science and materials electronic materials and processing electronic and photonic devices and systems luminescence and display materials, devices and processing.