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. ***
