In-situ and Operando Studies of Metastable and Transient States of Organic Semiconductor Thin Films

有机半导体薄膜亚稳态和瞬态的原位和操作研究

• 批准号: 1701774
• 负责人: Randall Headrick
• 金额: $ 42万
• 依托单位: University of Vermont & State Agricultural College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1701774&HistoricalAwards=false
• 关键词: situ; Operando; Studies; Metastable; Transient

Nontechnical Description: Organic semiconductors are designed at the molecular level to exhibit useful properties, and they promise the realization of a new generation of electronic circuits and solar cells. This research activity utilizes highly controllable methods of depositing ordered crystalline thin films from liquid solutions bearing small organic molecules. Experiments are being performed to understand ways that molecules organize from a disordered solution state into highly ordered crystalline solids. These molecular arrangements can also be sensitively tuned by stretching or compressing thin films, which may dramatically affect their properties. The experiments utilize polarized optical microscopy and X-ray scattering - two techniques which can help determine molecular ordering in the films. Electronic measurements are used to determine how easily electrons move in these materials. Calculations are also being performed to test theoretical predictions of the link between the molecular arrangement and electron motion. The societal impact of the research is amplified by innovative community outreach activities, including lectures and demonstrations designed to engage the public in a discussion of science and applications of energy, light, and nano-materials. This project provides graduate student training in a highly interdisciplinary area, and it introduces undergraduate students to X-ray science and thin film deposition technology.Technical Description: The rectangular hollow pen writer method can produce highly oriented films with controllable grain size that can exceed one centimeter, while in comparison, vapor deposited films typically have randomly oriented nanometer-scale grains. This project involves studies of the relationships between process parameters and film properties, such as grain size and orientation, strain, and defect density. Recent work suggests that many small molecule materials pass through a precursor stage during crystallization from solution, and this state can be unambiguously observed through a combination of optical and X-ray studies. Polarized optical video microscopy is sensitive to the nucleation and development of grain structure, while real-time optical spectroscopy is highly sensitive to local ordering, such as aggregation and molecular packing geometries. Real-time synchrotron X-ray diffraction is highly complementary because it is sensitive to long-range order, allowing time-resolved studies with millisecond resolution. Carrier transport in organic field effect transistors will also be studied as a function of applied strain by elastic stretching of thin films and substrates. The results will be related to ab-initio studies of the effect of strain on the electronic band structure and carrier transport properties. This research may lead to new environmentally responsible manufacturing methods based on roll-to-roll processes. These methods will underpin new technologies for low-cost, flexible electronics and solar cells.

非技术描述：有机半导体在分子水平上设计以表现出有用的特性，并承诺实现新一代的电子电路和太阳能电池。这项研究活动利用了具有较小有机分子的液体溶液的高度控制方法来沉积有序的结晶膜。正在进行实验，以了解分子从无序溶液状态组织到高度有序的晶体固体的方式。这些分子排列也可以通过拉伸或压缩薄膜来敏感地调节，这可能会极大地影响其特性。实验利用了极化光学显微镜和X射线散射 - 两种可以帮助确定膜中分子排序的技术。电子测量用于确定电子在这些材料中的容易移动。还进行了计算以测试分子布置与电子运动之间联系的理论预测。创新的社区外展活动（包括旨在让公众参与科学的讨论以及能源，光和纳米物质的应用程序）的演讲和示威活动来扩大研究的社会影响。 This project provides graduate student training in a highly interdisciplinary area, and it introduces undergraduate students to X-ray science and thin film deposition technology.Technical Description: The rectangular hollow pen writer method can produce highly oriented films with controllable grain size that can exceed one centimeter, while in comparison, vapor deposited films typically have randomly oriented nanometer-scale grains.该项目涉及研究过程参数与膜特性之间的关系，例如晶粒尺寸和方向，应变和缺陷密度。最近的工作表明，许多小分子材料从溶液结晶过程中经过前体阶段，并且可以通过光学和X射线研究的结合来明确观察到该状态。 极化的光学视频显微镜对晶体结构的成核和发展敏感，而实时光谱学对局部排序（例如聚集和分子填料几何形状）高度敏感。 实时同步加速器X射线衍射是高度互补的，因为它对远距离顺序敏感，可以通过毫秒分辨率进行时间分辨研究。还将通过薄膜和底物的弹性拉伸弹性伸展有机场效应晶体管中的载体传输作为施加应变的函数。结果将与Ab-Initio研究有关应变对电子带结构和载体传输特性的影响。这项研究可能会导致基于滚动流程的新的对环境负责的制造方法。 这些方法将为低成本，柔性电子和太阳能电池提供新技术。

项目成果

Dynamic processes in transient phases during self-assembly of organic semiconductor thin films

有机半导体薄膜自组装过程中瞬态动态过程

• DOI: 10.1039/d1me00078k
• 发表时间: 2022
• 期刊: Molecular Systems Design & Engineering
• 影响因子: 3.6
• 作者: Wan, Jing;Li, Yang;Benson, Jared;Miller, Richards;Zhernenkov, Mikhail;Freychet, Guillaume;Headrick, Randall L.
• 通讯作者: Headrick, Randall L.

Enhancement of charge transfer in thermally-expanded and strain-stabilized TIPS-pentacene thin films

• DOI: 10.1103/physrevresearch.2.033294
• 发表时间: 2020-08-24
• 期刊: PHYSICAL REVIEW RESEARCH
• 影响因子: 4.2
• 作者: Li, Yang;Wan, Jing;Headrick, Randall L.
• 通讯作者: Headrick, Randall L.