Nb-doped amorphous titanium oxide compact layer for formamidinium-based high efficiency perovskite solar cells by low-temperature fabrication

摘要

Low-temperature processed perovskite solar cells (PSCs) were prepared using an amorphous niobium-doped titanium oxide (Nb/TiOx) film as a compact layer (CL) combined with a brookite TiO2 mesoporous layer. Nb concentration of 4% in amorphous TiOx CL was found to improve the photocurrent-voltage performances of formamidinium (FA) and methylammonium (MA)-mixed perovskite, (FAPbI(3))(0.85)(MAPbBr(3))(0.15), and FA(0.85)Cs(0.15)PbI(3) perovskite solar cells, which were fabricated on 100 degrees C and 130 degrees C-annealed TiOx CLs; these solar cells exhibited conversion efficiencies up to 19.1% and 19.8%, respectively. The Nb/TiOx-based FA(0.85)Cs(0.15)PbI(3) perovskite cell obtained entirely by a low temperature process (130 degrees C or less) exhibited high stability against light soaking without encapsulation of the device.