The effects of crystallization on oligothiophene morphologies

Abstract

Polythiophenes have shown potential as inexpensive organic semiconductors because of their charge mobility properties. Small changes in structures can change the electronic and optical properties. Because oligothiophenes demonstrate the same electronic properties, have better solubility, and are easier to purify without defects, oligothiophenes are used as models for the polythiophenes. X-ray diffraction is an accepted method for studying the structure and arrangement of atoms in oligothiophenes; however, XRD requires crystalline solids for analysis. Obtaining suitable crystals can be difficult. In this paper, two crystallization techniques, vapor diffusion and zone sublimation, and the results are discussed. Raman spectroscopy, a type of vibrational spectroscopy, will give information about the structure of a molecule and can act as the molecular fingerprint of the molecule. Raman spectroscopy does not require crystalline solids and provides a relatively fast analysis. If the Willets lab can characterize the oligothiophenes by Raman spectroscopy, demonstrate distinguishable spectra for the different morphologies, and correlate this to the X-ray diffraction data, Raman spectroscopy will be an easier and faster means for analyzing the oligothiophenes.