Modeling electrical conductivity in porphyrin-based covalent organic frameworks COFs.

We employ density functional theory (DFT) to investigate porphyrin-based covalent organic frameworks (COFs) to improve electronic conductivity. For transport in the band-like regime, we evaluate the effect of metal substitution on the band alignment of metalloporphyrin COFs versus free-base-porphyrin COFs. For transport in the charge hopping regime, hopping rates were investigated by calculating reorganization energies, allowing insights into how electron-phonon coupling affects conductivity. To simulate the optical characterization of COFs to compare with experiments, we assess the accuracy of the model Bethe-Salpeter Equation (mBSE) approach when applied to porphyrins and COFs to capture excitonic transitions. We also investigate using the dielectric screening of molecular building blocks as an efficient approximation for the screening in periodic COFs. The results are expected to contribute to enhancing the photo- and ground-state conductivity of porphyrin-based COFs, with broad applications in porous materials such as photocatalysts and energy storage devices.