Ultrawide bandgap AlGaN ionizing radiation detectors

超宽带隙 AlGaN 电离辐射探测器

• 批准号: 1810116
• 负责人: MVS Chandrashekhar
• 金额: $ 37.09万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-15 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1810116&HistoricalAwards=false
• 关键词: Ultrawide; bandgap; AlGaN; ionizing; radiation

Radiation detectors are critically important for environmental controls and monitoring of hazardous radioactive materials at airports and many others safety critical locations. Advanced nuclear detection is a timely issue for national security, nuclear power plants, and for military security. This project aims to develop highly sensitive, compact nuclear detectors using aluminum gallium nitride crystalline films produced using the same technology which was used for blue-green-white light emitting diodes and it was awarded the 2014 Nobel Prize. More recently an innovative extension of this technology using Aluminum Gallium Nitride materials has led to ultraviolet LEDs for air and water purification and power electronics for electric vehicles and advanced military radars. These developments offer low-cost and high sensitivity performance, with the potential of integrating functionalities such as lighting, ultraviolet detection, as well as radio transmission on a single microchip. This project proposes material and device innovations, to explore the use of Aluminum Gallium Nitride technology for low-cost, compact and highly sensitive nuclear radiation detectors. The challenge is the production of high quality material, which can withstand high temperatures and harsh environments, such as in a nuclear power plant. The team proposes to produce these materials and working electrical devices to benchmark against existing higher cost, bulkier legacy technology. The proposed work will lead to the education of at least 2 PhD students, 1 African American and 1 military veteran currently in the team's group, who will go into jobs in either government research or advanced manufacturing. The proposed research will further cement University of South Carolina?s track record of excellence in Aluminum Gallium Nitride materials for harsh environment electronics. During the PI's sabbatical at Morgan State University, a historically black university in Baltimore, MD, the devices produced in this work will be integrated into senior design projects.The team proposes to develop a low-noise, high speed, ionizing radiation detector using ultra-wide bandgap aluminum gallium nitride epitaxial layers on aluminum nitride/sapphire templates. This ternary material is radiation hard and leads to devices with very low leakage currents even in harsh environments. It allows for monolithic integration with readout and power conditioning electronics, as well as other functionalities such as ultraviolet light sources. The proposed detector, a 2-5?m thick channel field effect phototransistor with a high internal current gain and low dark current will be grown by metalorganic chemical vapor deposition. It will be ideal for detecting pulses of radiation in Geiger mode, and eventually higher penetration radiation using thicker absorbing layers. The program exploits the shallow penetration deep ultraviolet light to improve materials development for thicker layers for soft beta radiation from Nickel-63. The ability to use monochromatic light enables characterization with spectral selectivity to the bandgaps, not possible with broadband beta-illumination. The team's initial experiments showed noise equivalent power 5fW, although these transistors had slow response times ~20s. Through a noise study, this was attributed to charge trapping at the aluminum nitride template/channel growth interface. The high current gain was partially a consequence of trapping induced photoconductivity. The growth solutions consist of electrically isolating this interface from the transistor channel, either with a thick strain engineered layer and/or a graded back barrier layer. Thus, any crystal growth strategy or device architecture that speeds up the device will lower photocurrent, but the Lorentzian noise arising from slow traps will also be reduced. Thus the tradeoff between current gain and speed, endemic to all detectors, is complicated by noise considerations, leading to the central question: How far can NEP and response time be decreased simultaneously by eliminating the influence of traps Initial analyses indicate that Nano-second to micro-second response times are possible, consistent with recombination times in direct gap semiconductors. The capability of engineering thick channel transistor layers directly translates to power electronics as well, as it enables the ability to block high voltages.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.

辐射探测器对于环境控制和监测机场和许多其他安全关键位置的危险放射性材料至关重要。先进的核检测是国家安全，核电站和军事安全的及时问题。该项目旨在使用使用相同技术生产的氮化铝制晶体膜开发高度敏感的紧凑型核检测器，该技术用于蓝绿色的光发射二极管，并获得了2014年诺贝尔奖。 最近，使用氮化铝材料对这项技术进行了创新的扩展，导致了用于空气和水净化的紫外线LED，以及电动汽车和先进军用雷达的电力电子设备。 这些发展提供了低成本和高灵敏度的性能，具有整合功能，例如照明，紫外线检测以及单个微芯片上的无线电传输。该项目提出了材料和装置创新，以探索使用氮化铝技术在低成本，紧凑和高度敏感的核辐射探测器中的使用。 挑战是生产高质量的材料，可以承受高温和恶劣的环境，例如在核电站中。该团队建议生产这些材料和工作设备，以对现有的较高成本，较大的旧技术进行基准测试。拟议的工作将导致至少有2名博士学位学生，1名非裔美国人和1名军人，目前该团队将在政府研究或高级制造业中从事工作。 拟议的研究将进一步巩固南卡罗来纳州的氮化铝材料的卓越纪录，用于苛刻的环境电子。 During the PI's sabbatical at Morgan State University, a historically black university in Baltimore, MD, the devices produced in this work will be integrated into senior design projects.The team proposes to develop a low-noise, high speed, ionizing radiation detector using ultra-wide bandgap aluminum gallium nitride epitaxial layers on aluminum nitride/sapphire templates.这种三元材料是辐射硬的，即使在恶劣的环境中，也导致泄漏电流非常低的设备。它允许与读数和功率调节电子设备以及其他功能（例如紫外线光源）进行整体集成。拟议的检测器是2-5？m厚的通道场效应光晶体管具有较高内部电流增益和低暗电流的光晶体管将通过金属有机化学蒸气沉积而生长。 它将是在Geiger模式下检测辐射脉冲的理想选择，最终使用较厚的吸收层渗透辐射。该程序利用了浅渗透深紫外线，以改善较厚层的材料开发，用于镍63的软β辐射。使用单色光的能力使表征能够以光谱的选择性对带隙进行选择性，而宽带β-弹片不可能。该团队的最初实验显示了噪声等效功率5FW，尽管这些晶体管的响应时间缓慢约20s。通过一项噪声研究，这归因于氮化铝模板/通道生长界面处的电荷捕获。高电流增益部分是捕获诱导的光导率的结果。生长溶液包括从晶体管通道的电气隔离该界面，该界面具有厚的应变工程层和/或分级后屏障层。因此，任何加速设备加速的晶体生长策略或设备架构都将降低光电流，但是慢速陷阱引起的洛伦兹噪声也将减少。因此，当前增益和速度之间的权衡是所有探测器所特有的，这是由于噪声考虑因素而复杂的，这导致了一个主要问题：通过消除陷阱的影响，NEP和响应时间可以同时减少多远，初步分析的影响表明，纳米秒与微秒响应时间可能是可能的，可能与直接GAP Emodoctucter的重组时间保持一致，这是一致的。工程厚通道晶体管层的能力也直接转化为电力电子设备，因为它能够阻止高压。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛影响的审查标准通过评估来通过评估来获得支持的。

项目成果

Trap characterization in ultra-wide bandgap Al 0.65 Ga 0.4 N/Al 0.4 Ga 0.6 N MOSHFET's with ZrO 2 gate dielectric using optical response and cathodoluminescence

使用光学响应和阴极发光对具有 ZrO 2 栅极电介质的超宽带隙 Al 0.65 Ga 0.4 N/Al 0.4 Ga 0.6 N MOSHFET 进行陷阱表征

• DOI: 10.1063/1.5125776
• 发表时间: 2019
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Jewel, Mohi Uddin;Alam, Md Didarul;Mollah, Shahab;Hussain, Kamal;Wheeler, Virginia;Eddy, Charles;Gaevski, Mikhail;Simin, Grigory;Chandrashekhar, MVS;Khan, Asif
• 通讯作者: Khan, Asif

Excimer laser liftoff of AlGaN/GaN HEMTs on thick AlN heat spreaders

• DOI: 10.1063/5.0064716
• 发表时间: 2021-09
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Md. Didarul Alam;M. Gaevski;M. Jewel;Shahab Mollah;A. Mamun;K. Hussain;Rich Floyd;G. Simin;M. Chandrashekhar;Asif Khan

Ultra-wide bandgap AlGaN metal oxide semiconductor heterostructure field effect transistors with high- k ALD ZrO 2 dielectric

具有高 k ALD ZrO 2 电介质的超宽带隙 AlGaN 金属氧化物半导体异质结构场效应晶体管

• DOI: 10.1088/1361-6641/ab4781
• 发表时间: 2019
• 期刊: Semiconductor Science and Technology
• 影响因子: 1.9
• 作者: Mollah, Shahab;Gaevski, Mikhail;Chandrashekhar, MVS;Hu, Xuhong;Wheeler, Virginia;Hussain, Kamal;Mamun, Abdullah;Floyd, Richard;Ahmad, Iftikhar;Simin, Grigory
• 通讯作者: Simin, Grigory

Photovoltaic and Photoconductive Action Due to PbS Quantum Dots on Graphene/SiC Schottky Diodes from NIR to UV

石墨烯/SiC 肖特基二极管上的 PbS 量子点从近红外到紫外的光伏和光电导作用

• DOI: 10.1021/acsaelm.9b00651
• 发表时间: 2019
• 期刊: ACS Applied Electronic Materials
• 影响因子: 4.7
• 作者: Kelley, Mathew L.;Letton, Joshua;Simin, Grigory;Ahmed, Fiaz;Love-Baker, Cole A.;Greytak, Andrew B.;Chandrashekhar, M. V.
• 通讯作者: Chandrashekhar, M. V.

Enhanced light extraction efficiency of micropixel geometry AlGaN DUV light-emitting diodes

• DOI: 10.35848/1882-0786/ac0fb8
• 发表时间: 2021-08-01
• 期刊: APPLIED PHYSICS EXPRESS
• 影响因子: 2.3
• 作者: Floyd, Richard;Gaevski, Mikhail;Khan, Asif
• 通讯作者: Khan, Asif