Chemical Bath Deposition of Mesoporous Sno2 to Improve Interface Adhesion and Device Operational Stability

The material and microstructure of the carrier-selective layers in the perovskite solar cells are important to determining their efficiency and stability. Planar tin dioxide (p-SnO 2 ) is the most commonly used inorganic electron transport layer, but there are few reports on its mesoporous devices due to the degradation of hole-blocking property after high temperature sintering. Here, based on the chemical bath deposition method, the aging process was optimized to realize low-temperature in-situ deposition of mesoporous SnO 2 (m-SnO 2 ) layer. It was found that the increased contact area could obviously improve the electron extraction ability of SnO 2 layer with its efficiency increased from 22.09% to 24.11%. Moreover, the formation of the interpenetrating interface structure significantly increases the adhesion of the perovskite/m-SnO 2 interface, and the extensional rigidity is enhanced more than 50% in comparison with perovskite/p-SnO 2 , which significant extends of operational stability. The introduction of m-SnO 2 layer improves operational stability of the unencapsulated device retain 90% of their original PCE after 1000 h under 1-sun illumination and with continuous maximum power point tracking