An amino-phthalocyanine additive enhances the efficiency of perovskite solar cells through defect passivation in mixed-halide films

Although perovskite solar cells (PSCs) can be easy to process and display exceptional optoelectronic properties, the presence of defects and poor control over crystallization can adversely affect their efficiency and long-term stability. In this study, we employed iron(II)-2,9,16,23-tetraamino-phthalocyanine (FeTAP) as a small-molecule additive capable of defect passivation in a mixed-halide perovskite (MHP). In particular, we used an additive engineering treatment protocol to introduce FeTAP into the MHP layer to significantly suppress perovskite defects, improve charge extraction, and inhibit perovskite degradation. A PSC incorporating a FeTAP-modified perovskite layer exhibited a power conversion efficiency (PCE) of 18.81% and retained 72.5% of its initial PCE after storage for 30 days. Thus, adding FeTAP to the MHP film significantly enhanced the efficiency and stability of the resulting PSC.