Micro-molecule modifier enables prolonged shelf-life of perovskite ink for efficient and scalable inkjet-printed solar cells

Abstract

Stable, eco-friendly perovskite inks are essential for developing scalable, efficient perovskite solar cells (PSCs). Herein, a micro-molecule modification strategy using propylene carbonate (PC), a Lewis base with a strong dipole moment, is employed to enhance the stability and processability of perovskite eco-inks. Incorporating 3 vol% PC significantly prolongs ink shelf-life by more than 15 days, suppresses byproduct formation, and prevents nozzle clogging, while delivering exceptional film-thickness uniformity (similar to 96%) and a smooth surface morphology. Ambient-processed inkjet-printed (IJP) PSCs fabricated with PC-modified inks achieve a powerconversion efficiency (PCE) of 18.59%, surpassing the unmodified control (17.38%), and retain >90% of their initial PCE after nine days (three days for reference) of ink storage under highly humid conditions. This enhancement is attributed to the improved microstructural homogeneity, larger grain formation, and effective grain-boundary passivation induced by the dipolar micro-molecule additive. The micro-molecule modifier controls defect formation in perovskites, as confirmed by a DFT study. The estimated upscaling factor for the micro-molecule-modified device to mini module is 11.9% rel/dec (relative upscaling loss per decade) (similar to 13.5% rel/dec for reference). These findings establish micro-molecular engineering as a sustainable pathway for stable, high-performance, and scalable perovskite photovoltaics, paving the way for industrial IJP applications.