Polarons play a central role in the electronic and optical properties of organic materials, and, given their relevance for various applications, are the focus of cross-disciplinary research at the intersection of chemistry, physics, and materials science. The spectral lineshape of the mid-infrared absorption provides valuable information about the "hole" polaron delocalization lengths. Here, we present a comprehensive theory describing the spatial coherence length of polarons in COFs, with specific focus on Covalent Organic Framweorks, revelaing a simple relationship between the oscillator strength of the infrared absorption band and the polaron coherence function.<sup>1,2 </sup>Emphasis is placed on determining the fundamental nature and origin of the components polarized along the intra- and inter-framework directions of different COFs, as well as the dependence of these components on the spatial distribution of disorder, framework topology, and position of the dopant counter anion relative to the COF pores. We demonstrate that simple optical probes such as steady state absorption can be efficiently used to extract critical information about the polaron coherence lengths, quantities which are crucial for our detailed understanding of energy and charge transport processes in organic materials. Our analysis provides conclusive evidence of why iodine doped COFs have so far shown lower bulk conductivity compared to doped polythiophenes.

Unraveling the effect of defects and chemical doping on photophysics and charge transport in covalent organic frameworks

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.