Monitoring the Evolution of Molecular Structure in Transistors by Interfacial Spectroscopy

技术描述：本项目利用特定界面振动和频率产生谱技术研究有机场效应晶体管有源界面上的分子振动及其取向。这项工作的基本任务是光谱监测操作设备中界面的演变，以深入了解界面分子结构和功能之间的关系。这些活动确定了铸造溶剂和介电界面偶极子在提高薄膜晶体管电性能方面的作用。本项目还探索了磷酸锆自组装纳米介电体在界面有机结构上的应用。此外，研究小组利用多路复用和频率光谱测量了热退火过程中介电层和有机半导体层中分子结构和载流子积累的时间演变。这些实验的原位性质提供了从功能设备内部研究材料响应的新视角，不仅可以描述变化，还可以描述结构变化的时间尺度，以及这些特性如何与宏观电响应相关。非技术描述：晶体管是每个数字设备的基本组成部分之一，从手机到杂货店的收银台扫描仪。在操作过程中，电流沿着界面移动，原子或分子在该区域的排列决定了电荷流动的效率。该项目使用专门的光学测量来确定这些设备中的分子在微观水平上是如何排列的，以及它们对下垫表面的化学反应和热处理的反应。该项目是跨学科的，旨在培养精通材料加工、电学和光学表征技术的下一代科学家。此外，作为“草原大学”项目的一部分，研究小组每年夏天组织并指导为期三天的农村推广活动，在活动中，他们通过动手演示，将初中年龄的参与者观察到的材料特性与他们熟悉的现实世界技术联系起来。

Technical Description: This project uses interface-specific vibrational sum frequency generation spectroscopy to study molecular vibrations and their orientations at the active interface in organic field-effect transistors. An underlying mission of this work is to spectroscopically monitor the evolution of the interface in operational devices to gain insight into the relationships between interfacial molecular structure and function. The activities establish the role of casting solvents and interfacial dipoles at the dielectric interface in enhancing the electrical performance of thin film transistors. The project also explores the use of zirconium phosphonate self-assembled nanodielectrics on the interfacial organic structure. In addition, the research team uses multiplexed sum frequency spectroscopy to measure the temporal evolution of molecular structures and carrier accumulation in the dielectric and organic semiconductor layers during thermal annealing. The in-situ-nature of these experiments provides a new perspective on the materials response from inside the functioning device, with the potential to describe not only what changes, but also what the timescales of structural change are and how these properties relate back to the macroscopic electrical response.Non-Technical Description: Transistors are one of the basic building blocks of every digital device, from cell phones to grocery store check-out scanners. During operation, electricity moves along an interface and the arrangement of atoms or molecules in this region determines how efficiently the charges can flow. This project uses specialized optical measurements to determine how the molecules in these devices are ordered at the microscopic level, and how they respond to the chemistry of the underlying surfaces and to thermal processing treatments. The project is interdisciplinary, producing next-generation scientists who are skilled in materials processing, and electrical and optical characterization techniques. In addition, the research team organizes and directs a three-day-long rural outreach event each summer as a part of the University on the Prairie program where they use hands-on demonstrations to make connections between the materials properties observed by the junior high school aged participants and the real-world technologies with which they are familiar.