Surface Analytical Investigation on Organic Donor-Acceptor Interfaces

University Of Rochester, Rochester NY

Investigators

Abstract

Technical: This project studies the interfaces in small-molecule organic photovoltaic materials using surface analytical probes. The objective of the experimental research is to understand the fundamental aspects of the interface electronic structures and the exciton dissociation at the donor-acceptor interfaces. The main experimental techniques include x-ray photoemission spectroscopy, ultraviolet photoemission spectroscopy, and inverse photoemission spectroscopy. Exciton dissociation at the donor-acceptor interfaces is measured by observing the quenching of the photoluminescence spectroscopy intensity. The charge transfer dynamics across the donor-acceptor interfaces is investigated with time-resolved two-photon photoemission spectroscopy. X-ray photoemission spectroscopy is used to study the interface chemistry. The morphology of the organic layers is characterized with scanning tunneling microscopy, atomic force microscopy, and near-field scanning optical microscopy. The project will also test the concepts developed through the surface/interface analysis by fabricating and characterize simple organic photovoltaic devices fabricated based on the findings of surface analytical investigations. Non-technical: The project addresses basic research issues in a topical area of materials science with high technological relevance. It addresses fundamental understanding of organic photovoltaics, a promising candidate important for renewable and environmentally friendly energy source. A major part of the project is educating and training graduate and undergraduate students through interdisciplinary research in advanced organic materials and devices and in materials surface/interface characterization. A strong focus of the program is providing early exposure of research to middle and high school students through programs including University of Rochester Pre-College Experience in Physics for women.