Tunnel Junction Based AlGaN Ultraviolet Lasers

基于隧道结的 AlGaN 紫外激光器

• 批准号: 2034140
• 负责人: Shamsul Arafin
• 金额: $ 40万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2034140&HistoricalAwards=false
• 关键词: Tunnel; Junction; Based; AlGaN; Ultraviolet

While visible blue lasers have been demonstrated with excellent performance, realizing ultraviolet lasers at wavelengths shorter than 300 nm is still challenging despite efforts over more than a decade by various research groups. The principal problem for electrically-powered lasers is related to achieving a reasonable electrical p-conductivity in laser materials through which electrical current will flow. This makes it challenging to operate lasers at a reasonable electrical power. This project proposes an innovative approach that utilizes tunnel junctions (TJs) which alleviates the p-conductivity problem of laser materials without sacrificing optical performance of the device. These short-wavelength ultraviolet lasers are recently found to be useful for sterilizing surfaces or objects, as one of the precautionary steps to prevent the global spread of the coronavirus (COVID-19). Arguably, this application could be enabled by light emitting diodes (LEDs) in this wavelength regime. However, energy-inefficient LEDs achieved to-date are large, complicated, and expensive, which essentially limits their applicability in these key areas. In addition to high impact research advancement, this project will also support interdisciplinary education activities in nanoscience and nanotechnology. Because the proposed research project crosses different disciplines of science and engineering, such as optics, materials science, electrical engineering, physics, and chemistry, it will lead to a range of potential, hands-on learning activities that can engage students of varying backgrounds. In addition, the scientific insights and technological advances stemming from the research will also broadly impact the field of photonics by enabling operation in this underdeveloped spectral region. There is a tremendous need for electrically-pumped (EP) and continuous-wave (CW) operating AlGaN-based diode lasers in the ultraviolet (UV)­B (320­280 nm) and UV-C (280–200 nm) wavelength regimes due to a wide range of emerging applications including plant growth lighting, water sterilization, trace gas sensing, curing polymers, and stimulating the formation of anti-cancerogenic substances. The primary objective of the proposed research is to design and demonstrate tunnel-injected EP and CW-operating UV lasers with wavelengths of emission ranging from 320 nm to 280 nm. P-type doping and formation of low-resistive p-ohmic contacts are the key challenges for electrically-pumped UV laser diodes. This work proposes to use novel interband tunnel junctions for ultra-wide band gap AlGaN up to 70% aluminum composition in order to overcome this principal challenge. The work performed within this project will generate new fundamental knowledge on the AlGaN-material system and its several important properties including refractive index, carrier interband tunneling through band-tail states and bandgap narrowing, as well as absorption in ultra-thin layers with quantum confinement. The proposed research involves a novel device concept to realize such highly demanding light sources based on the ultra-wide band gap materials. The device knowledge gained from this research will establish a foundation for demonstrating laser devices with emission in the entire deep-UV spectral regime. The early stage of the project aims to demonstrate broad-area Fabry-Pérot lasers using high-bandgap n­AlGaN cladding regions on both sides of the active region. The devices will then be tested in pulsed mode, which will help determine various unknown material properties of high Al composition structures. In the second stage of the project, this project aims to demonstrate application-suited CW-operating lasers by employing narrow­ridge structures with optimized epitaxial structures. The radically new approach proposed here will enable new scientific understanding in the areas of ultra-wide band gap materials and optical devices as well as could establish the platform for a new class of AlGaN-based UV laser technology.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

虽然可见蓝色激光器已被证明具有优异的性能，但尽管各个研究小组十多年来一直在努力，但实现波长小于 300 nm 的紫外激光器仍然具有挑战性。电动激光器的主要问题与在电流流过的激光材料中实现合理的 p 电导率有关。这使得以合理的电功率运行激光器变得具有挑战性。该项目提出了一种利用隧道结 (TJ) 的创新方法，可在不牺牲器件光学性能的情况下缓解激光材料的 p 电导率问题。最近发现这些短波长紫外线激光器可用于对表面或物体进行消毒，作为防止冠状病毒（COVID-19）全球传播的预防措施之一。可以说，这种应用可以通过该波长范围内的发光二极管 (LED) 来实现。然而，迄今为止实现的低能效 LED 体积庞大、复杂且昂贵，这从本质上限制了它们在这些关键领域的适用性。除了高影响力的研究进展外，该项目还将支持纳米科学和纳米技术的跨学科教育活动。由于拟议的研究项目跨越了科学和工程的不同学科，例如光学、材料科学、电气工程、物理和化学，因此它将带来一系列潜在的实践学习活动，可以吸引不同背景的学生。此外，该研究产生的科学见解和技术进步也将通过在这个不发达的光谱区域中进行操作来广泛影响光子学领域。由于包括植物生长照明、水消毒、痕量气体传感、固化聚合物和刺激形成聚合物等在内的广泛新兴应用，对紫外 (UV)B (320280 nm) 和 UV-C (280–200 nm) 波长范围内的电泵 (EP) 和连续波 (CW) 操作的基于 AlGaN 的二极管激光器有着巨大的需求。 抗癌物质。拟议研究的主要目标是设计和演示发射波长范围为 320 nm 至 280 nm 的隧道注入 EP 和 CW 操作紫外激光器。 P 型掺杂和低电阻 p 欧姆接触的形成是电泵浦紫外激光二极管的关键挑战。这项工作建议使用新型带间隧道结用于超宽带隙 AlGaN（铝成分高达 70%），以克服这一主要挑战。该项目中进行的工作将产生关于 AlGaN 材料系统及其几个重要特性的新基础知识，包括折射率、通过带尾态的载流子带间隧道和带隙变窄，以及具有量子限制的超薄层的吸收。所提出的研究涉及一种新颖的设备概念，以实现基于超宽带隙材料的高要求光源。从这项研究中获得的设备知识将为演示在整个深紫外光谱范围内发射的激光设备奠定基础。该项目的早期阶段旨在展示使用有源区两侧的高带隙 nAlGaN 包层区域的大面积法布里-珀罗激光器。然后，这些器件将以脉冲模式进行测试，这将有助于确定高铝成分结构的各种未知材料特性。在该项目的第二阶段，该项目旨在通过采用具有优化外延结构的窄脊结构来演示适合应用的连续波操作激光器。这里提出的全新方法将使人们对超宽带隙材料和光学器件领域产生新的科学认识，并为新型基于 AlGaN 的紫外激光技术建立平台。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Interband tunnel junctions for AlGaN Ultra-Violet light emitting diodes (Conference Presentation)

AlGaN 紫外发光二极管的带间隧道结（会议演示）

• DOI: 10.1117/12.2658149
• 发表时间: 2023
• 期刊: SPIE Conference Proceeding
• 作者: Dominic Merwin Xavier, Agnes Maneesha;Ghosh, Arnob;Rahman, Sheikh Ifatur;Arafin, Shamsul;Rajan, Siddharth
• 通讯作者: Rajan, Siddharth

Low voltage drop AlGaN UV-A laser structures with transparent tunnel junctions and optimized quantum wells

具有透明隧道结和优化量子阱的低压降 AlGaN UV-A 激光器结构

• DOI: 10.1088/1361-6463/ad039c
• 发表时间: 2023
• 期刊: Journal of Physics D: Applied Physics
• 作者: Ghosh, Arnob;Dominic Merwin Xavier, Agnes Maneesha;Hasan, Syed M. N.;Rahman, Sheikh Ifatur;Blackston, Alex;Allerman, Andrew;Myers, Roberto C.;Rajan, Siddharth;Arafin, Shamsul
• 通讯作者: Arafin, Shamsul

Demonstration of AlGaN Tunnel Junction p-Down UV Light Emitting Diodes

AlGaN 隧道结 p-Down 紫外发光二极管演示

• 发表时间: 2023
• 期刊: EMC
• 作者: Dominic Merwin Xavier, Agnes Maneesha;Ghosh, Arnob: Rahman;Allerman, Andrew;Arafin, Shamsul;Rajan, Siddharth
• 通讯作者: Rajan, Siddharth

Multi-active region AlGaN UV LEDs with transparent tunnel junctions

具有透明隧道结的多有源区 AlGaN UV LED

• DOI: 10.35848/1882-0786/acea1b
• 发表时间: 2023
• 期刊: Applied Physics Express
• 影响因子: 2.3
• 作者: Dominic Merwin Xavier, Agnes Maneesha;Ghosh, Arnob;Rahman, Sheikh Ifatur;Allerman, Andrew;Verma, Darpan;Myers, Roberto C.;Arafin, Shamsul;Rajan, Siddharth
• 通讯作者: Rajan, Siddharth

Towards Electrically-Pumped AlGaN UV-A Lasers with Transparent Tunnel Junctions

具有透明隧道结的电泵浦 AlGaN UV-A 激光器

• DOI: 10.1364/cleo_si.2023.sf2q.5
• 发表时间: 2023
• 作者: Ghosh, Arnob;Xavier, Agnes M.;Rahman, Sheikh Ifatur;Allerman, Andrew;Rajan, Siddharth;Arafin, Shamsul
• 通讯作者: Arafin, Shamsul