Interface Characterization of Organic Bistable Devices

本计画旨在研究一种新观察到的有机薄膜元件中的电致变色行为，即电导率的几个数量级的变化。通过在有机薄膜器件中引入薄金属膜，产生两个金属/有机界面，促进了双稳态。理解界面的作用被认为是阐明这种有机电致变色器件机理的关键因素。该项目的总体目标是通过材料，界面和设备调查获得对设备操作机制的基本理解。界面电子结构，可能的化学反应和相互扩散，能级排列和HOMO-LUMO位置的基本理解，寻求通过使用表面分析工具，包括X射线和紫外光电子能谱（XPS，UPS），和逆光电子能谱（IPES）。扫描探针显微镜，包括原子力显微镜（AFM），扫描隧道显微镜（STM）和相关的光谱将被用来检查薄膜的形貌，表面和界面，以及在纳米尺度上的器件特性。FTIR和UV-Vis（反射模式和透射模式）也将用于研究有机和有机金属络合物膜的各个方面。该项目解决了与电子/光子材料相关的基础研究问题，具有技术相关性，并强调研究和教育的整合。该项目的一个主要重点是教育和培训研究生和本科生在一个跨学科领域，涵盖有机电子材料，器件，表面和界面分析。***

This project aims to investigate a newly observed electrical bistable behavior, several orders of magnitude change in conductivity, in organic thin-film devices. The bistability is facilitated by introducing a thin metal film in an organic thin film device, which produces two metal/organic interfaces. Understanding the role of the interfaces is considered a key factor in elucidating the mechanism of such organic bistable devices. The overall goal of the project is to gain fundamental understanding of the device operation mechanism through materials, interface, and device investigations. Basic understanding of interface electronic structure, possible chemical reactions and interdiffusion, and energy level alignment and HOMO-LUMO positions, is sought through use of surface analytical tools including x-ray and ultraviolet photoemission spectroscopy (XPS, UPS), and inverse photoemission spectroscopy (IPES). Scanning probe microscopy, including atomic force microscopy (AFM), scanning tunneling microscopy (STM) and related spectroscopies will be employed to examine the film morphology, surfaces and interfaces, and device characteristics in nanometer scale. FTIR and UV-Vis (both in the reflection mode and transmission mode) will also be used to study aspects of organic and organo-metallic complex films. %%% The project addresses fundamental research issues associated with electronic/photonic materials having technological relevance and emphasizes the integration of research and education. A major focus of the project is on educating and training graduate and undergraduate students in an interdisciplinary field covering organic electronic materials, devices, and surface and interface analysis. ***