High‐Performance and Large‐Area Inverted Perovskite Solar Cells Based on NiOx Films Enabled with A Novel Microstructure‐Control Technology

The improvement in the efficiency of inverted perovskite solar cells (PSCs) is significantly limited by undesirable contact at the NiO X /perovskite interface. In this study, a novel microstructure‐control technology is proposed for fabrication of porous NiO X films using Pluronic P123 as the structure‐directing agent and acetylacetone (AcAc) as the coordination agent. The synthesized porous NiO X films enhanced the hole extraction efficiency and reduced recombination defects at the NiO X /perovskite interface. Consequently, without any modification, the power conversion efficiency (PCE) of the PSC with MAPbI 3 as the absorber layer improved from 16.50% to 19.08%. Moreover, the PCE of the device composed of perovskite Cs 0.05 (MA 0.15 FA 0.85 ) 0.95 Pb(I 0.85 Br 0.15 ) 3 improved from 17.49% to 21.42%. Furthermore, the application of the fabricated porous NiO X on fluorine‐doped tin oxide (FTO) substrates enabled the fabrication of large‐area PSCs (1.2 cm 2 ) with a PCE of 19.63%. This study provides a novel strategy for improving the contact at the NiO X /perovskite interface for the fabrication of high‐performance large‐area perovskite solar cells.