Triphenylamine hydrophobic surface prepared by low-temperature solution deposition for stable and high-efficiency SnO2 planar perovskite solar cells

Organic-inorganic halide perovskites have shown many advantages with photovoltaic performance. The crystal quality of perovskite film and the tolerance in humidity environment still need to be improved due to its instability problem. In this paper, triphenylamine (TPA) as a hydrophobic surface is deposited on perovskite film to prevent the infiltration of moisture and hydrophilic additives from entering the perovskite film. In addition, the introduction of TPA/CB mixed solution could promote the volatile speed of high boiling point solvent DMSO and accelerate the crystallization process of perovskite films. Compared with the devices without TPA, the power conversion efficiency (PCE) was increased from 17.10% to 19.13%. The devices with TPA can retained over 85% of their initial PCE in air with about 60% humidity for 800 h without encapsulation, while the PCEs of the none-TPA devices dropped to 52% of their initial values. The strategy can effectively improve the stability and photoelectric performance of solar cells, and the SnO(2 )electron transport layer replaced the traditional TiO2 to realize the whole process of low temperature (<150 degrees C) preparation of PSCs. (C) 2020 Elsevier B.V. All rights reserved.