Antisolvent solubilization achieves simultaneous passivation of shallow and deep defects in perovskite solar cells

Abstract

Resolving the inherent defects at the interfaces and grain boundaries of perovskite films is crucial for achieving highly efficient and stable perovskite solar cells (PSCs). This study introduces an antisolvent solubilization (AS) approach to enhance the solubilization of the bulk organic ammonium salt 2-Thiophenemethylammonium Iodide (ThMAI), which has limited solubility in low-polarity antisolvents. The results demonstrated that the AS approach could effectively passivate both shallow and deep defects in organic–inorganic hybrid perovskites (OIHPs). Furthermore, the ThMAI prepared using the AS method could react with excess PbI₂ and facilitate the crystallization of the OIHPs, thereby improving light absorption, suppressing non-radiative recombination, and enhancing carrier extraction. As a result, PSCs prepared by using the AS method achieved a power conversion efficiency (PCE) of 23.69%, representing a 10% PCE improvement compared to normal devices. PSCs based on the AS method also demonstrated significantly improved heat and humidity stability.