Electrode stress passivation via oxide titanium amorphous interlayer for flexible non-fullerene organic photovoltaics

Abstract

Research to improve the performance and stability of flexible organic solar cells (F–OSCs) during their fabrication is necessary for their extensive future application. Polyethylene naphthalate (PEN), which has high transparency, thermal stability, and solvent resistance, was selected as the substrate for flexible devices. IEICO-4F, a non-fullerene acceptor (NFA), and a PTB7-Th donor were used to fabricate high-performance F–OSCs with a bulk heterojunction structure. These F–OSCs were shown to have a slightly higher performance than rigid substrate-based NFA-OSCs. Furthermore, the electron transport ability and bending stability of the F–OSCs were improved by introducing an oxide titanium amorphous interlayer (O-TiAI) to form a smooth passivation layer. Then, the stability of the flexible NFA-OSCs was improved when direct morphology and electrode damage occurred by applying external electrode stress in a harsh environment, and the mechanical and electrical stability was improved by introducing the amorphous interlayer. © 2022 Elsevier B.V.