Multiscale Scanning Tunneling Microscopy Study of Self-Assembly Phenomena in Two-Dimensional Polycrystals of π-Conjugated Polymers: The Case of Regioregular Poly(dioctylbithiophene-alt-fluore-none)

摘要

The development of so-called "organic electronics" in the past decade is inherently associated with the progress in the synthesis and processing of new π-conjugated systems. In particular, dramatic increases in the performances of organic electronic devices such as light-emitting diodes (LEDs), solar cells, lasers, and field-effect transistors (FETs) have been achieved as a result of 1) development of new synthetic routes to molecules or macromolecules of desired topology, 2) improvement in the purification of the obtained compounds, and 3) better control of their supramolecular organization via appropriate processing techniques. This is particularly true for π-conjugated polymers, which constitute an important group of organic electronic materials. It is clear that further progress in this domain of research requires a detailed investigation of the effect of the structural order at different length scales on the electronic properties of these polymers. In many cases, this is not easy because of the morphological complexity of the majority of polymeric semiconductors.