Large Planar π-Conjugated Porphyrin for Interfacial Engineering in p-i-n Perovskite Solar Cells.

In hybrid organic-inorganic perovskite solar cells (PSCs), interfacial engineering can efficiently improve the photovoltaic performance. In this work, the planar π-conjugated porphyrin, zinc(II) 5,10,15,20-tetrakis[5-(p-acetylthiopentyloxy)phenyl]porphyrin, was developed to modify the interface between poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) and perovskite. The modified devices increased their highest power conversion efficiency (PCE) to 14.05% relative to 11.35% for the reference devices without modification. Such enhancement in efficiency is mainly attributed to the improved open-circuit voltage (Voc) and fill factor (FF), which benefit from fast hole-extraction and low charge recombination after the employment of well-aligned interlayer.