Aluminate Coupling Agent-Induced Interface Engineering for Enhanced Performance in NiOx-Based Inverted Perovskite Solar Cells

Abstract

Inverted perovskite solar cells (PSCs) using NiO_x as the hole transport layer face significant buried interface issues, severely limiting their photovoltaic performance potential. We have developed an interface modification strategy for NiO_x based inverted PSCs using an aluminum coupling agent, distearoyl isopropoxy aluminates (AL18). This molecule anchors to the NiO_x surface through an alcoholysis reaction with its alkoxy and hydroxyl groups, forming a monolayer that reduces non-radiative recombination and prevents degradation at the NiO_x/perovskite interface. This modification led to a photovoltaic conversion efficiency of 24.04% in small-scale (0.09 cm²) PSCs. Additionally, a large-area (14 cm²) perovskite solar cell module achieved over 21.07% efficiency and retained 94% of its initial performance after 30 hours under AM1.5 G illumination.