CAREER: Understanding Photo-thermoelectric Phenomena in Bulk and Nanomaterials for Better Optical Sensing

职业：了解块状和纳米材料中的光热电现象以实现更好的光学传感

• 批准号: 2340728
• 负责人: Heng Wang
• 金额: $ 57.88万
• 依托单位: Illinois Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-07-01 至 2029-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2340728&HistoricalAwards=false
• 关键词: CAREER; Understanding; Photo; thermoelectric; Phenomena

NontechnicalInfrared detectors have important uses in industry, agriculture, healthcare, and national security. Most detectors are based on absorption of infrared light by a semiconductor that in turn generates an electrical current. However, their sensitivity decreases, and the noise increases, as the wavelength increases. A different phenomenon involving both light and heat shows promise for infrared detectors with high sensitivity across a wide range of wavelengths. This phenomenon, called the photo-thermoelectric effect, is the electronic response of a material when exposed to both light and a temperature gradient. This CAREER award will advance the fundamental understanding of the photo-thermoelectric effect, including underlying causes and impact of materials properties. The PI’s team will synthesize single crystal films and nanomaterials and study them by a suite of advanced characterization techniques. The aim of this project is to develop materials that would enable infrared of detectors with unprecedented light-sensing performance and spectral response. The project has a multi-pronged educational effort to address the nation’s semiconductor workforce needs. The PI will develop training modules and rapid certificate programs and explore curriculum reform focused on problem-solving. Undergraduate students will participate in research and the PI will engage in outreach to K-12 students themed in semiconductor technology.TechnicalPhoto-thermoelectric phenomena arise from varied mechanisms. While some can be described with classic frameworks, others occur far from equilibrium and are not well understood. In order to address this knowledge gap, the PI will develop strategies and techniques to separate contributions from different mechanisms, allowing for the quantification and interpretation of each. The drift of photon-generated carriers will be examined using modified scanning photocurrent microscopy. Contributions from hot carriers will be distinguished using transient photo-thermoelectric voltage measurements. The influence of materials properties will be studied using lead sulfide as an archetype, comparing single crystalline thin films with nanoparticles assemblies of interest for slow hot carrier cooling caused by phonon bottlenecks. The nature of defects and their influence will be studied using a modified thermoelectric spectroscopy technique. These research efforts will be complemented by pump-probe spectroscopy, and synchrotron diffraction and absorption. This research will enable rational design of infrared sensing devices based on photo-thermoelectric effects where different factors constructively contribute.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.

非技术攻击探测器在行业，商定，医疗保健和国家安全方面具有重要用途。大多数探测器基于通过半导体对感染光抽象的抽象，而半导体又产生电流。但是，随着波长的增加，它们的灵敏度降低，噪声增加。涉及光和热量的不同现象显示出对在各种波长范围内具有高灵敏度的感染探测器的希望。这种现象称为光心电效应，是材料的电子响应，当暴露于光和温度梯度时。该职业奖将提高对照片 - 热电效应的基本理解，包括基本原因和材料物业的影响。 PI的团队将合成单晶膜和纳米材料，并通过一系列高级特征技术进行研究。该项目的目的是开发能够提供具有前所未有的光感应性能和光谱响应的检测器的材料。该项目有多方面的教育努力，以满足该国的半导体劳动力需求。 PI将开发培训模块和快速证书计划，并探索针对解决问题的课程改革。本科生将参与研究，PI将与以半导体技术为主题的K-12学生进行外展。技术机制引起的技术 - 透明电视现象。虽然有些可以用经典框架描述，但另一些框架远非均衡，尚不清楚。为了解决这一知识差距，PI将制定策略和技术，以将贡献与不同机制分开，从而允许对每个机制进行量化和解释。光子生成的载体的漂移将使用改进的扫描光电流显微镜检查。热载体的贡献将使用瞬态光电电压测量进行区分。材料特性的影响将使用硫化铅作为原型进行研究，将单晶薄膜与感兴趣的纳米颗粒组件进行比较，用于由光子瓶颈引起的缓慢热载体冷却。缺陷的性质及其影响将使用改良的热电学光谱技术进行研究。这些研究工作将通过泵探针光谱以及同步加速器衍射和抽象来完成。这项研究将基于光学电性效应，使红外敏感性设备的合理设计具有建设性的贡献。该奖项反映了NSF的法定任务，并通过使用基金会的智力优点和更广泛的影响来审查标准，通过评估通过评估来获得支持。