Enhancing structure and optoelectronic properties of ambient-processed FAPbI3 perovskites through phenylethylammonium iodide doping

Abstract

Ambient-processed perovskite solar cells (PSCs) have become a focal point of discussion in recent years, aiming to facilitate the industrialization and practical application of these devices. Traditionally, PSCs have been prepared only in controlled environments. However, recent research highlights material engineering, particularly the organic doping of perovskite halides, as a promising strategy to achieve ambient-processable PSC performance. This study examines the effects of phenylethylammonium iodide (PEAI) on the structural and optoelectrical properties of ambient-processed FAPbI₃ perovskite. Ambient processed FAPbI₃ perovskite was obtained by doping with hexamine molecule. The introduction of PEAI into the ambient-processed FAPbI₃ lattice enhances the crystallinity and optoelectrical properties of the perovskite, with optimal results observed at a PEAI concentration of 2 mg/mL. This optimal incorporation of PEAI results in a power conversion efficiency (PCE) of 20.9 %, with a short circuit current (J_sc) of 24.8 mA/cm², a V_oc of 1.09 V, and a fill factor (FF) of 0.775. This represents a 31.4 % improvement compared to the pristine PSC device, which has a PCE of 15.9 %. These findings highlight the potential of PEAI incorporation in enhancing the stability and performance of FAPbI₃ PSCs through 2D structural enforcement and surface defect passivation, improving crystallinity.