Nanoscale Pumping Effect of Perovskite via Supported Bilayer Electron Transport Layer for Efficient Printable Mesoscopic Solar Cells

Recently, enhancing the photovoltaic performance of printable mesoscopic perovskite solar cells (p‐MPSCs) poses a significant challenge, particularly in improving the diffusion of perovskite precursor solutions during device assembly. In this research, effective gap‐driven diffusion of the precursor solution perovskite is successfully achieved, leading to the formation of well‐filled and crystallized perovskite through TiO 2 nanorod arrays. By incorporating upper‐layer TiO 2 nanoparticles, a bilayer electron transport layer with dual crystal phase is developed, establishing a cascaded energy level structure that exhibits superior capabilities in electron collection and directional transport. The effective suppression of nonradiative recombination and efficient charge transfer result in notable enhancements in both open‐circuit voltage and short‐circuit current density. Consequently, the power conversion efficiency of p‐MPSCs devices based on MAPbI 3 γ ‐butyrolactone solution increases from 14.32% to 16.07% (highest reported value in the literature is 16.21%). These findings highlight a novel interface engineering approach for the fabrication of high‐performance p‐MPSCs devices.