Conjugated polymers (CPs) constitute the base of organic thin film optoelectronic devices, such as organic photovoltaic solar cells (OSCs) and organic light emitting devices (OLEDs). Deposited onto large areas of any shape they critically contribute to the development of self-powered, smart and ubiquitous communication platforms. Operational performance and fabrication from 'green' solutions compatible with large-area coating or printing technologies are key requirements for their commercial implementation. Applying self-assembly strategies, CPs can be prepared in the form of water dispersible nanoparticles being of actual interest for achieving improved device performance. In this work we present novel pathways for the design of improved organic thin film optoelectronic devices by marrying nanoparticles of CPs (CPNPs) with 2D sheets of graphene oxide (GO). Using poly(3-hexylthiophene) (P3HT) as benchmark CP, we demonstrate the game-changing role of GO in tuning the excitonic aggregate behavior of P3HTNPs and the efficient formation P3HTNPs-GO charge-transfer complexes. Thin films thereof reveal improved separation of photo-generated charge carriers. Integration into a photoelectrochemical device shows significantly improved photoactivity. Moreover, the thin films reveal unique molecular switching behavior. The possibility to overcome external performance limitations and to employ 'green' processing technologies offers exciting possibilities for further progress in the field of organic thin film optoelectronic devices.

EU Horizon 2020 Marie Sklodowska-Curie grant 642742 ("Enabling Excellence"), Spanish Ministry MINEICO (ENE2016-79282-C5-1-R), Government of Aragón (Recognized Group DGA-T03-17R).

Resumen del trabajo presentado al Nano Application Workshop, celebrado en Munich (Alemania) del 19 al 21 de septiembre de 2018.

Peer Reviewed