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.

非技术红外探测器在工业、农业、医疗保健和国家安全中具有重要用途。大多数探测器基于半导体吸收红外光，进而产生电流。随着波长的增加，它们的灵敏度会降低，噪声也会增加。光和热的一种不同现象为涉及广泛波长范围的高灵敏度红外探测器带来了希望。这种现象称为光热电效应，是材料在暴露于光和热时的电子响应。该职业奖将促进对光热电效应的基本理解，包括材料特性的根本原因和影响，目的是合成单晶薄膜和纳米材料，并通过一套先进的表征技术来研究它们。该项目的重点是开发能够使红外探测器具有前所未有的光传感性能和光谱响应的材料。该项目将进行多管齐下的教育工作，以满足国家半导体劳动力的需求。和快速证书课程，并探索以解决问题为重点的课程改革，而 PI 将参与以半导体技术为主题的 K-12 学生的推广活动。技术光热电现象有多种机制。为了解决这一知识差距，PI 将开发策略和技术来区分不同机制的贡献，从而量化和解释每个机制的漂移。光子产生的将使用改进的扫描光电流显微镜检查载流子。将使用瞬态光热电电压测量来区分热载流子的贡献。将使用硫化铅作为原型来研究材料特性的影响，比较单晶薄膜与感兴趣的纳米颗粒组件。对于由声子瓶颈引起的缓慢热载流子冷却，将使用改进的热电光谱技术来研究缺陷的性质及其影响。这项研究将使基于光热电效应的红外传感装置的合理设计成为可能，其中不同的因素具有建设性的贡献。该奖项的法定使命，并通过使用基金会的智力价值和更广泛的评估被认为值得支持。影响审查标准。