High-Performance and Large-Area Inverted Perovskite Solar Cells Based on NiO_x 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 MAPbI₃ as the absorber layer improved from 16.50% to 19.08%. Moreover, the PCE of the device composed of perovskite Cs_0.05(MA_0.15FA_0.85)_0.95Pb(I_0.85Br_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 cm²) 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.