Reduced hysteresis and enhanced air stability of low-temperature processed carbon-based perovskite solar cells by surface modification

Low temperature processed carbon-based perovskite solar cells (C-PSCs) have gained great interest because of low cost and ease fabrication. By replacing the Au electrode with carbon, stable suited for mass-production process can be made. However, power conversion efficiencies (PCEs) C–PSCs still lag behind that PSCs contact. Here we explore (?150 °C) C-PSCs with, where a two-step method is used to prepare mixed-ion lead films, tin oxide (SnO2) electron transport layer, poly(3-hexylthiophene-2,5-diyl) (P3HT) hole layer carbon electrode, resulting in devices PCE 14.0%. Moreover, hexyl trimethylammonium bromide (HTAB) was introduced improve interface between P3HT. Perovskite grains were remarkably enlarged into micrometer-size defects reduced. As result, champion 16.1% obtained, mainly due enhanced fill factor from 0.67 0.73. The modification by HTAB molecule an effective way passivate facilitate carrier at perovskite/HTL interface. Unencapsulated showed excellent stability over 1500 h stored under ambient air (relative humidity ? 50 ± 10%).