Monitoring the Evolution of Molecular Structure in Transistors by Interfacial Spectroscopy

技术说明：本计画利用界面特定振动和频产生光谱法，研究有机场效电晶体中主动界面的分子振动及其取向。这项工作的一个基本使命是光谱监测操作设备中的界面的演变，以深入了解界面分子结构和功能之间的关系。这些活动确立了浇铸溶剂和介电界面处的界面偶极子在增强薄膜晶体管的电性能中的作用。 该项目还探索了使用磷酸锆自组装纳米电介质对界面有机结构的影响。 此外，研究小组使用多路复用和频光谱来测量热退火过程中介电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对材料响应的新视角，不仅可以描述什么变化，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，从手机到杂货店结账扫描仪。 在操作期间，电流沿着界面移动，并且该区域中的原子或分子的布置决定电荷可以流动的效率。 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，以及它们如何对底层表面的化学反应和热处理进行响应。该项目是跨学科的，培养了精通材料加工以及电气和光学表征技术的下一代科学家。此外，研究团队每年夏天组织和指导为期三天的农村外展活动，作为草原大学计划的一部分，他们使用动手演示来连接初中学生观察到的材料属性和他们熟悉的现实世界技术。

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.