Conference Paper

In Organic Photovoltaic devices (OPVs), the optimization and stabilization of the photoactive layer´s
morphology is crucial to attain high efficiency and long-term stability. One approach to reach morphological
stability can rely on the formation of stable supramolecular structures complying with the optimal
characteristics, that is, an interpenetrated network of the electron-donor and the electron-acceptor, within the
nanoscale.
We designed novel -conjugated small molecules functionalized with barbituric acid and N-methylated
barbituric acid moieties to provide self-assembling properties and form stable supramolecular networks. The
novel compounds are derivatives of ITIC, one of the non-fullerene acceptors most used in OPVs. We found that
the barbiturate moieties perform as good electron-accepting groups and enable adjusting the lowest
unoccupied molecular orbital (LUMO), while inducing self-assembling properties in the new compounds, as
indicated by Atomic Force Microscopy (AFM) analysis. In this communication, we present the synthesis, the
electronic structure calculations and optical and electrochemical characterisation of the new compounds as well
as their applications, as the electron-acceptor, in OPV devices.
This work was funded by Fundação para a Ciência e Tecnologia (FCT-Portugal) through Instituto de
Telecomunicações (contract no. UIDB/50008/2020) and PhD Grant to B. Oliveira (2021.04873.BD).