Electronic Structure in Thin Film Organic Semiconductors

摘要

Despite the technological and scientific importance of semiconducting organic materials, there have been few studies of their valence band electronic structure using modern synchrotron radiation-based spectroscopic methods. The combination of high resolution soft x-ray emission, soft x-ray absorption, and high resolution photoemission spectroscopy was used in this program to measure the detailed electronic structure of a selection of organic semiconductor thin films. The films were grown in a custom built organic molecular beam epitaxy chamber attached to a multi-technique spectrometer chamber stationed on a soft x-ray undulator beamline at the National Synchrotron Light Source. Information was obtained on the element and site specific valence band partial density of states, chemical state, and orbital bonding in the films. Materials studied include aluminum tris-8- hydroxyquinoline (Alq3), titanyl phthalocyanine (TiO-Pc), and vanadyl phthalocyanine (VO-Pc).