Collaborative Research: Amorphous-Crystalline Switching in Organic-Inorganic Hybrid Semiconductors

合作研究：有机-无机混合半导体中的非晶-晶体转换

• 批准号: 2114121
• 负责人: Michael Toney
• 金额: $ 17.49万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2114121&HistoricalAwards=false
• 关键词: Collaborative; Research; Amorphous; Crystalline; Switching

Nontechnical Description: Hybrid organic-inorganic perovskite (HOIP) semiconductors represent an emerging materials class that offers a unique opportunity to combine and individually tailor desirable characteristics from organic and inorganic systems within a single molecular-scale composite, and such systems already provide outstanding properties for next generation solar cells, light-emitting devices, and photodetectors. Current HOIP research generally focuses on the crystalline state, in which constituent atoms repeat in a periodic and well-ordered fashion. With this project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, Prof. David Mitzi at Duke University and Prof. Michael Toney at the University of Colorado and their research groups will investigate methods to extend beyond the current state-of-the-art in HOIPs to demonstrate and understand how controllable disorder can be introduced within HOIPs through an accessible melt and glass state, and how this disorder can be employed to significantly expand the range of properties for the HOIP family. Such research targets creation of design rules to guide future development of meltable and glass forming HOIPs and to understand how properties of the glass and melt states differ from the crystalline state. Reversible switching between crystalline and glass states, employing small changes in temperature, vastly broadens the prospective application space for HOIPs to include low-power phase-change memory, neuromorphic computing, advanced sensing, and reconfigurable photonics. The research closely connects with education and outreach. Involved undergraduate, graduate and postdoctoral researchers engage with the national labs for structure-property studies, and this experience gets conveyed to the broader student body through an on-going student-oriented energy materials seminar series. Structure-property data for the glasses are made broadly available to the community through a perovskite-focused database, representing the first collection of HOIP glass state data. Project research connects to traditionally underserved STEM communities through an NSF REU, "Nanoscale Detectives -- Elucidating the Structure and Dynamics of Hybrid Perovskite Systems," and through a Pre-Collegiate Development Program that prepares first generation/low-income students from inner-city and rural areas.Technical Description: This project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, combines targeted synthesis, with detailed structure and property characterization for a new class of hybrid organic-inorganic perovskite (HOIP) semiconductors that offers facile access to melt and glassy states, focusing on two key directions. First, the project uses targeted HOIP synthesis using developed design rules for low HOIP melting temperature and prospective glass-crystalline switching, seeking to broaden the family of HOIPs that can effectively access melt/glass states. Successfully created materials are structurally characterized using X-ray/neutron scattering techniques, coupled with extended X-ray absorption fine structure, Raman spectroscopy and rheometry. This intensive characterization captures the extended crystalline and local melt/glass state structures, as well as underlying mechanical properties. Second, while HOIP crystalline state properties are broadly studied and understood, the current project connects HOIP melt and glass local structure with corresponding thermal and optoelectronic properties, studied using differential scanning calorimetry and various optical spectroscopies, targeting a pathway for enhancing and tuning these properties. By exploring fundamental structure-property connections associated with the HOIP melt and glass states, the research seeks to ultimately create a pathway for predictably designing HOIPs with targeted glass and melt state properties, as is increasingly already possible for the crystalline state.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.

非技术描述：混合有机-无机钙钛矿（HOIP）半导体代表了一种新兴的材料类别，其提供了独特的机会来在单个分子尺度复合材料内联合收割机并单独定制来自有机和无机系统的期望特性，并且这样的系统已经为下一代太阳能电池、发光器件和光电探测器提供了出色的性能。目前HOIP的研究主要集中在结晶状态，其中组成原子以周期性和有序的方式重复。在NSF材料研究部的固态和材料化学计划的支持下，杜克大学的大卫·米茨教授和科罗拉多大学的迈克尔·托尼教授及其研究小组将研究超越当前状态的方法。HOIP中的技术，以证明和理解如何通过可接近的熔体和玻璃态在HOIP中引入可控的无序，以及如何利用这种无序来显著扩展HOIP家族的性质范围。此类研究旨在创建设计规则，以指导可熔融和玻璃成型HOIP的未来开发，并了解玻璃和熔融状态的性质与结晶状态的差异。晶体和玻璃状态之间的可逆切换，采用温度的微小变化，大大拓宽了HOIP的应用空间，包括低功耗相变存储器，神经形态计算，先进的传感和可重构光子学。这项研究与教育和推广密切相关。参与的本科生，研究生和博士后研究人员与国家实验室进行结构-性能研究，并通过正在进行的以学生为导向的能源材料研讨会系列将这种经验传达给更广泛的学生团体。通过以钙钛矿为重点的数据库，玻璃的结构-性质数据被广泛地提供给社区，代表了HOIP玻璃状态数据的第一个集合。项目研究通过NSF REU，“纳米级探测器--阐明混合Perception系统的结构和动力学”，以及通过准备来自内城和农村地区的第一代/低收入学生的大学预科发展计划，连接到传统上服务不足的STEM社区。该项目由NSF材料研究部的固态和材料化学计划支持，结合了靶向合成，详细的结构和性能表征的一类新的混合有机-无机钙钛矿（HOIP）半导体，提供了容易获得熔融态和玻璃态，专注于两个关键方向。首先，该项目使用针对低HOIP熔融温度和预期玻璃-晶体转换的开发设计规则进行有针对性的HOIP合成，寻求扩大可以有效进入熔融/玻璃状态的HOIP家族。使用X射线/中子散射技术，结合扩展X射线吸收精细结构、拉曼光谱和流变仪，对成功创建的材料进行结构表征。这种密集的表征捕获了扩展的结晶和局部熔融/玻璃态结构，以及潜在的机械性能。其次，虽然HOIP结晶状态属性被广泛研究和理解，但目前的项目将HOIP熔体和玻璃局部结构与相应的热和光电性能联系起来，使用差示扫描量热法和各种光谱进行研究，旨在增强和调节这些性能。通过探索与HOIP熔体和玻璃态相关的基本结构-性质联系，该研究旨在最终创建一种途径，用于可预测地设计具有目标玻璃和熔体态性质的HOIP，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查进行评估来支持的搜索.