Blading of Conformal Electron-Transport Layers in p-i-n Perovskite Solar Cells

Perovskite solar cells (PSCs) are promising to reduce the cost of photovoltaic system due to their low-cost raw materials and high-throughput solution process; however, fabrication of all the active layers in perovskite modules using a scalable solution process has not yet been demonstrated. Herein, the fabrication of highly efficient PSCs and modules in ambient conditions is reported, with all layers bladed except the metal electrode, by blading a 36 ± 9 nm-thick electron-transport layer (ETL) on perovskite films with a roughness of ≈80 nm. A combination of additives in phenyl-C₆₁ -butyric acid methyl ester (PCBM) allows the PCBM to conformally cover the perovskites and still have a good electrical conductivity. Amine-functionalized molecules are added to enhance both the dispersity of PCBM and the affinity to perovskites. A PCBM dopant of 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine (N-DMBI) recovers the conductivity loss induced by the small amine molecules. PSCs (0.08 cm² ) fabricated by the all-blading process reache an average efficiency of 22.4 ± 0.5% and a champion efficiency of 23.1% for perovskites with a bandgap of 1.51 eV, with much better stability compared to evaporated ETL PSCs. The all-bladed minimodule (25.03 cm² ) shows an aperture efficiency of ≈19.3%, showing the good uniformity of the bladed ETLs.