Electrical mitigation of radiation-induced defects in AlGaN/GaN photovoltaic detectors

AlGaN/GaN 光伏探测器中辐射引起的缺陷的电气缓解

• 批准号: 1802208
• 负责人: Leonid Chernyak
• 金额: $ 32.5万
• 依托单位: The University of Central Florida Board of Trustees
• 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: 2018-08-15 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1802208&HistoricalAwards=false
• 关键词: Electrical; mitigation; radiation; induced; defects; Electrical; mitigation; radiation; induced; defects

Non-technical: Ultraviolet photodetectors have many uses, such as chemical and biological analysis or flame detection. Damage by energetic particles degrades the sensitivity of ultraviolet photodetectors in harsh radiation environments. This project will lead to a dramatic increase in the recovery of photodetectors based on gallium nitride (GaN). This outcome will be achieved by electrical tailoring of a fundamental property of GaN, the electron diffusion length, by in-situ charge injection under applied voltage. Photodetector sensitivity will recover completely and return to the original state prior to irradiation. The project will advance the fundamental understanding of the nature of point and extended defects in GaN-based semiconductors and devices. The project will integrate research and education at the graduate and undergraduate levels and features an active industrial partner.Technical: This project focuses on electrical mitigation of irradiation-induced defects by charge injection into ultraviolet photodetectors based on gallium nitride (GaN). The ultimate aim is to produce radiation hard and efficient devices. This project hinges on the PI's previous findings that charge injection into p-type GaN leads to considerable changes in the material's electronic properties, particularly the carrier diffusion length. These changes result in an order of magnitude enhancement of the photodetector quantum efficiency. It is therefore possible to improve performance of photodetectors, affected by radiation, using short pulses of solid-state forward-bias charge injection into GaN p-i-n devices. The project will lead to a better understanding of the interaction between wide gap semiconductors and highly energetic particles, including electrons, gamma-ray photons, and protons, as well as of the nature of radiation-induced defects. Charge injection will result in enhanced minority electron diffusion length in the top p-type absorption layer of a photodetector, thus increasing the quantum efficiency for the device and "healing" the adverse impact of gamma-rays, protons, electrons and other radiation types. A unique combination of electrical, optical and structural studies in the PI's lab will shed light on the mechanism, which is responsible for the effect of interest. Studies of minority carrier diffusion length and lifetime will be carried out in independent experiments using electron beam-induced current and ultrafast time-resolved cathodoluminescence at various temperatures. Polychromatic continuous-wave cathodoluminescence will be employed for assessment of irradiation impact on threading dislocation density in GaN. Finally, deep level transient spectroscopy will allow studies of radiation-induced point defects. The ultimate goal is to correlate charge injection regimes (current; voltage; duration) and irradiation doses, thus proceeding towards control of photodetector performance and recovery from radiation damage by purely electrical means.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.

非技术：紫外光电探测器具有许多用途，例如化学和生物学分析或火焰检测。通过能量颗粒的损害降解了刺激性辐射环境中紫外线光电探测器的灵敏度。该项目将导致基于硝酸盐（GAN）的光电检测器的回收率急剧增加。通过在施加电压下通过原位电荷注入GAN（电子扩散长度）的基本特性的基本特性来实现此结果。光电探测器灵敏度将完全恢复，并在辐照之前恢复到原始状态。该项目将进一步了解基于GAN的半导体和设备中点的性质和扩展缺陷的基本理解。该项目将整合研究生和本科级别的研究和教育，并具有活跃的工业合作伙伴。技术：该项目的重点是通过电荷注入基于硝酸盐（GAN）的紫外线光电探测器对辐照诱导的缺陷进行电气缓解。最终目的是生产辐射硬有效的设备。该项目取决于PI先前的发现，即对P型GAN充电会导致材料的电子特性，尤其是载体扩散长度的大幅变化。这些变化导致光电探测器量子效率的数量级增强。因此，使用固态前向偏置电荷的短脉冲注入到GAN P-I-N设备中，可以改善受辐射影响的光电探测器的性能。该项目将更好地理解宽间隙半导体与高能颗粒（包括电子，伽马射线光子和质子）的相互作用，以及辐射诱导的缺陷的性质。电荷注入将导致少数元电子扩散长度在光电探测器的顶部P型吸收层中增强，从而提高了设备​​的量子效率，并“治愈”了伽马射线，质子，电子和其他辐射类型的不良影响。 PI实验室中电气，光学和结构研究的独特组合将阐明该机制，这是对感兴趣的影响的原因。在各种温度下，将在独立的实验中对少数载体扩散长度和寿命进行研究。将采用多色连续波发光来评估辐照对gAN中螺纹脱位密度的影响。最后，深度瞬态光谱法将允许研究辐射诱导的点缺陷。最终的目标是将电荷注入机制（电流；电压；持续时间）和辐射剂量相关联，从而朝着控制光电探测器的性能和通过纯电气手段从辐射损害中恢复的恢复。这一奖项反映了NSF的法定任务，并被认为是通过该基金会的知识分子优点和广泛影响的评估来评估的，并被视为值得通过评估的支持。