Collaborative Research: Fundamental Study of Environmentally Stable and Lead-Free Chalcogenide Perovskites for Optoelectronic Device Engineering

合作研究：用于光电器件工程的环境稳定、无铅硫系钙钛矿的基础研究

• 批准号: 2013640
• 负责人: Nikhil Koratkar
• 金额: $ 37.05万
• 依托单位: Rensselaer Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2013640&HistoricalAwards=false
• 关键词: Collaborative; Research; Fundamental; Study; Environmentally

Nontechnical:Solar energy is one of the most promising green technologies and could enable humankind to meet its future energy needs in a sustainable manner. The development of high performance, low cost and environmentally friendly solar cells is therefore critical for our energy security. One of the most promising new class of materials for solar energy is metal halide perovskites. The power conversion efficiency of solar cells made from such perovskites has witnessed an unprecedented rate of increase. Despite their outstanding performance, perovskites have poor stability and are prone to photo-decomposition due to ion migration. There are also serious issues with their environmental compatibility as the highest performing perovskite solar cells contain lead, a highly poisonous metal. Furthermore, lead iodide, a common decomposition product of these materials, is carcinogenic. In the face of these challenges, it is necessary to identify and develop high performing and lead free perovskites that are intrinsically stable under light irradiation and when exposed to the environment. This project will investigate solar cells based on chalcogenide perovskites—an alternative to metal halide perovskites typically used in solar cells. These materials are free of lead and use a chalcogen such as sulfur, which could result in superior stability. This project could lead to a new class of high performance and environmentally stable solar cells and photodetectors with transformative impacts.Technical:A number of fundamental science and device engineering issues will be addressed in this project in order to enable the successful deployment of chalcogenide perovskite based materials in high performing optoelectronic devices such as photo-detectors and solar cells. These include: (1) understanding the nature of defects in these materials, and how they affect the dark current, band structure, mid gap states, and carrier lifetimes. The chalcogenide perovskite material growth conditions will be carefully controlled, to minimize such defects; (2) Alloying strategies to optimize the band gap of chalcogenide perovskite based materials will be theoretically predicted using first-principles density functional theory calculations. Such alloying will also be experimentally realized to demonstrate chalcogenide perovskite materials with optimized bandgaps; (3) State of the art machine learning tools (guided by ab initio calculations and experiments) will be used to systematically screen the entire family of chalcogenide perovskite materials in order to find the optimal material and alloying combination; (4) Photo-detector and solar cell devices constructed using the optimized chalcogenide perovskite material will be developed and systematically characterized to demonstrate the proof of concept. The above tasks will together provide the fundamental knowledge that is needed to demonstrate high performing, environmentally stable and lead free optoelectronic devices using the family of chalcogenide perovskite 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.

非技术：太阳能是最有前途的绿色技术之一，可以使人类以可持续的方式满足未来的能源需求。因此，开发高性能、低成本和环保的太阳能电池对我们的能源安全至关重要。金属卤化物钙钛矿是最有前途的太阳能新材料之一。由这种钙钛矿制成的太阳能电池的能量转换效率以前所未有的速度提高。尽管钙钛矿具有优异的性能，但由于离子迁移，钙钛矿的稳定性较差，容易发生光分解。由于性能最高的钙钛矿太阳能电池含有铅，一种剧毒金属，因此其环境兼容性也存在严重问题。此外，这些物质的常见分解产物碘化铅具有致癌性。面对这些挑战，有必要确定和开发在光照射和暴露于环境时具有内在稳定性的高性能无铅钙钛矿。该项目将研究基于硫系钙钛矿的太阳能电池，这是太阳能电池中通常使用的金属卤化物钙钛矿的替代品。这些材料不含铅，并使用硫等硫，这可能导致优越的稳定性。这个项目可能会导致一种新型的高性能和环境稳定的太阳能电池和光电探测器，具有变革性的影响。技术：为了使硫系钙钛矿基材料在高性能光电器件（如光电探测器和太阳能电池）中的成功应用，该项目将解决许多基础科学和器件工程问题。这些包括：(1)了解这些材料中缺陷的性质，以及它们如何影响暗电流、能带结构、中隙状态和载流子寿命。将硫系钙钛矿材料的生长条件仔细控制，尽量减少这类缺陷；(2)利用第一性原理密度泛函理论计算，对优化硫系钙钛矿基材料带隙的合金化策略进行理论预测。这种合金化也将在实验上实现，以证明具有优化带隙的硫系钙钛矿材料；(3)最先进的机器学习工具（以从头计算和实验为指导）将用于系统筛选整个硫系钙钛矿材料家族，以找到最佳的材料和合金组合；(4)利用优化的硫系钙钛矿材料构建的光电探测器和太阳能电池器件将被开发和系统表征，以证明概念的验证。上述任务将共同提供使用硫系钙钛矿材料家族展示高性能，环境稳定和无铅光电器件所需的基本知识。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。