Authors:
Marc-Antoine Stoeckel, Yoann Olivier, Marco Gobbi, Dmytro Dudenko, Vincent Lemaur, Mohamed Zbiri, Anne A. Y. Guilbert, Gabriele D'Avino, Fabiola Liscio, Andrea Migliori, Luca Ortolani, Nicola Demitri, Xin Jin, Young Gyun Jeong, Andrea Liscio, Marco V (...)
Marc-Antoine Stoeckel, Yoann Olivier, Marco Gobbi, Dmytro Dudenko, Vincent Lemaur, Mohamed Zbiri, Anne A. Y. Guilbert, Gabriele D'Avino, Fabiola Liscio, Andrea Migliori, Luca Ortolani, Nicola Demitri, Xin Jin, Young Gyun Jeong, Andrea Liscio, Marco Vittorio Nardi, Luca Pasquali, Luca Pasquali, Luca Razzari, David Beljonne, Paolo Samorì, Emanuele Orgiu, Emanuele Orgiu
(Read More)
Abstract:
Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of disorder, both internal and external (i.e. related to the interactions with the dielectric layer), especially for n-type materials. Internal dynamic disorder stems from large thermal fluctuations both in intermolecular transfer integrals and (molecular) site energies in weakly interacting van der Waals solids and sources transient localization of the charge carriers. The molecular vibrations that drive transient localization typically operate at low (...)
Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of disorder, both internal and external (i.e. related to the interactions with the dielectric layer), especially for n-type materials. Internal dynamic disorder stems from large thermal fluctuations both in intermolecular transfer integrals and (molecular) site energies in weakly interacting van der Waals solids and sources transient localization of the charge carriers. The molecular vibrations that drive transient localization typically operate at low-frequency (< a-few-hundred cm-1), which renders it difficult to assess them experimentally. Hitherto, this has prevented the identification of clear molecular design rules to control and reduce dynamic disorder. In addition, the disorder can also be external, being controlled by the gate insulator dielectric properties. Here we report on a comprehensive study of charge transport in two closely related n-type molecular organic semiconductors using a combination of temperature-dependent inelastic neutron scattering and photoelectron spectroscopy corroborated by electrical measurements, theory and simulations. We provide unambiguous evidence that ad hoc molecular design enables to free the electron charge carriers from both internal and external disorder to ultimately reach band-like electron transport.
(Read More)