Impact of Low-Frequency Vibrations on Charge Transport in High-Mobility Organic Semiconductors

Despite decades of intensive studies of charge transport in organic semiconductors (OSs), understanding of mechanisms underpinning efficient charge transport in them remains elusive. Recently, it has been suggested that low-frequency (LF) vibrations are a limiting factor of charge transport in high-mobility OSs. Nevertheless, the relationship between the molecular structure, crystal packing, LF vibrations, and charge transport is still obscured. This hinders the focused search of high-mobility OSs so that researchers rely mainly on trial-and-error method. This review presents theoretical and experimental approaches to studying the LF vibrations and their role in charge transport with a focus on recent results. It is anticipated that tight cooperation between experimentalists and theorists will yield an advanced understanding of LF vibrations in OSs and their impact on charge transport. This will guide the design of novel high-mobility organic semiconductors for organic electronics.