UC Irvine

Organic semiconductors have shown promise not only as alternative materials for silicon- based devices, but also as a gateway to a new paradigm of printable, biocompatible, wearable, and generally ubiquitous electronics. Considerable research effort has been devoted to elucidating structure-function relationships and charge transport phenomena in organic materials at the sub-20 nm length scale, where various key device-relevant electronic processes occur. However, the construction of precisely defined model systems at these length scales, which emulate the properties of π-stacked or single molecule organic semiconductors remains as an important unmet challenge. To address this challenge, we have developed novel methodology for constructing length- and sequence-controlled molecular wires that can self-assemble into well- defined interfaces for charge transport studies. We have characterized the electronic structure and charge transfer dynamics at these interfaces with various techniques, including electrochemistry, synchrotron-based spectroscopy, and scanning tunneling microscopy. Our findings hold broad general relevance for understanding structure-function relationships in arbitrary organic electronic materials, nanoscale charge transfer phenomena at device-relevant organic/inorganic interfaces, and electrical conductivity in biological and bioinspired systems.