Study on oligo(aniline)-based hole transport layer for organic solar cells

Abstract

Interfacial engineering of electrode manipulation has determined to be an effective solution for enhancing the photovoltaic performance of organic solar cells (OSCs). In comparison to the exclusive development of novel photoactive materials, the study of interfacial buffer materials is seriously left behind and the contribution of electrode modification to power conversion efficiency (PCE) improvement is considered important. In this contribution, we report the doping system of a macromolecular derivative originated from aniline – phenyl/phenyl end-capped tetra(aniline) (PTA) and an aryl sulfonic acid (NSO-2), which can be employed as hole transport layer (HTL) for OSCs with conventional architecture. As revealed for the first time, devices fabricated from newly developed HTL on PM6:Y6 active layer system exhibited comparative PCE with control device of PEDOT:PSS (14.94% vs. 15.22%), which is the best reported PCE among PANI/OANI-based HTLs. Moreover, the device fabricated with PTA:NSO-2 HTL also emphasizes their better stability than PEDOT:PSS through moisture exposure experiment. Therefore, this result motivates the further optimization of the doping system to achieve the higher photovoltaic performance.