Hydrogen-bonded conjugated small molecules in organic electronics

Organic semiconductors have become highly important for next-generation electronic devices. However, further research is needed to enhance their charge-transport properties and long-term stability. These challenges largely originate from their solid-state structure, as organic semiconductors are molecular solids whose organisation is governed by very weak non-covalent interactions. Accordingly, the weakness of intermolecular interactions increases the chances of having structural disorder and generating defects, which detrimentally affect the performance of organic semiconductors. Therefore, controlling molecular organisation is a key objective. Hydrogen bonding is particularly effective for promoting solid-state self-assembly and gaining certain control over molecular organisation. The strength of hydrogen bonds, their directionality, and the broad range of functional groups and structures that can act as hydrogen-bond donors and acceptors have encouraged their rational incorporation into the molecular design of organic semiconductors. This Feature Article presents a review of the structural approaches developed to enhance the performance of materials based on small molecules through the integration of hydrogen-bond donor and acceptor sites within the conjugated framework. It also discusses the implementation of these materials in different types of electronic devices.