Collaborative Research: Photomechanical Behavior in Photovoltaic Semiconductors

合作研究：光伏半导体中的光机械行为

• 批准号: 2330728
• 负责人: Feng Yan
• 金额: $ 22.81万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2024-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2330728&HistoricalAwards=false
• 关键词: Collaborative; Research; Photomechanical; Behavior; Photovoltaic

Photovoltaic semiconductors are capable of converting light into electricity. They are the principal components of solar cells that provide renewable energy from sunlight. These semiconductors tend to fail in a brittle manner, limiting their general use to small-scale applications. New evidence shows though that the mechanical behavior of photovoltaic semiconductors is sensitive to sunlight, exhibiting the potential of relative malleability under illumination. The mechanisms underlying such light-mechanical coupling effect remains elusive. This award supports fundamental research to elucidate how light-induced excitation controls the mechanical behavior of photovoltaic semiconductors. The new knowledge is expected to offer strategies to design highly stable and durable photovoltaic devices, such as solar cells, transistors, light-emitting diodes, and photodetectors, providing the basis for extensive engineering applications. This award will also offer education and training for graduate and undergraduate students in interdisciplinary areas of mechanics, materials science and engineering, and photophysics. The award will promote diversity by involving women and underrepresented minorities in research activities.The photomechanical behavior of photovoltaic semiconductors is determined by light-induced deformation mechanisms such as dislocation and twinning. In this project, a multiscale modeling and experimental framework will be used to accurately characterize the influence of photoinduced electron-hole excitation on the dislocation and twining mechanics in cadmium telluride, a prototype photovoltaic semiconductor. On the sub-atomic scale, advanced quantum mechanics simulations will be performed to determine the influence of electron-hole pair on the energy and force barriers of dislocation and twin nucleation, as well as dislocation mobility. On the atomic scale, the carrier concentration dependent mechanisms of the dislocation-dislocation and dislocation-twin interactions will be characterized using reactive force field based molecular dynamics simulations. On the mesoscale, the light-illumination effect on the stress-strain behavior will be quantified by developing an atomically-informed crystal plasticity model that incorporates dislocation slip and deformation twinning. Theoretical predictions will be validated through mechanical testing and materials characterizations using advanced experimental techniques, including nanoindentation, scanning probe microscopy, transmission electron microscopy, and electron backscatter diffraction. This work will result in a new physical picture of the deformation mechanism of photovoltaic semiconductors under light illumination, and provide a comprehensive understanding of light-mechanical coupling effects in general photovoltaic materials.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.

光伏半导体能够将光转化为电能。它们是太阳能电池的主要组成部分，从阳光中提供可再生能源。这些半导体往往会以脆性方式失效，从而限制了它们在小规模应用中的一般用途。新证据表明，光伏半导体的机械行为对阳光敏感，在光照下表现出相对可塑性的潜力。这种光-机械耦合效应的机制仍然难以捉摸。该奖项支持基础研究，以阐明光诱导激发如何控制光伏半导体的机械行为。新知识预计将为设计高度稳定和耐用的光伏器件（如太阳能电池、晶体管、发光二极管和光电探测器）提供策略，为广泛的工程应用奠定基础。该奖项还将为力学、材料科学与工程以及光物理学等跨学科领域的研究生和本科生提供教育和培训。该奖项将通过让女性和代表性不足的少数群体参与研究活动来促进多样性。光伏半导体的光机械行为是由位错和孪晶等光致变形机制决定的。在该项目中，将使用多尺度建模和实验框架来准确表征光致电子空穴激发对碲化镉（一种原型光伏半导体）中位错和缠绕力学的影响。在亚原子尺度上，将进行先进的量子力学模拟，以确定电子空穴对对位错和孪晶成核的能量和力势垒以及位错迁移率的影响。在原子尺度上，位错-位错和位错-孪生相互作用的载流子浓度依赖机制将使用基于反作用力场的分子动力学模拟来表征。在介观尺度上，通过开发一种包含位错滑移和变形孪生的原子信息晶体塑性模型，可以量化光照射对应力应变行为的影响。理论预测将通过机械测试和材料表征来验证，使用先进的实验技术，包括纳米压痕、扫描探针显微镜、透射电子显微镜和电子背散射衍射。这项工作将产生光照射下光伏半导体变形机制的新物理图像，并提供对一般光伏材料中光-机械耦合效应的全面理解。该奖项反映了 NSF 的法定使命，并被认为值得支持使用基金会的智力价值和更广泛的影响审查标准进行评估。