Self-encapsulated semi-transparent perovskite solar cells with water-soaked stability and metal-free electrode

Semi-transparent and self-encapsulated perovskite solar cells could be fabricated by simply laminating the front sub-cell (ITO/poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS)/ CH3NH3PbI3) and back sub-cell (FTO/compact-TiO2/mesoporous-TiO2/CH3NH3PbI3), without vacuumevaporating metal electrode. The addition of chlorobenzene (CB) between two perovskite layers accelerated perovskite crystals interfusion and close interfacial contact from two separated sub-cells, which contributed to perovskite film with high crystallinity and light absorption in laminated cells. The selfencapsulated perovskite solar cell (device area of 0.39 cm(2)) with CB treatment not only showed power conversion efficiency of 6.9%, but also existed excellent stability even if soaking in water for 24 h. This novel approach to fabricate semi-transparent, solution-processible, cost-effective and high-stable perovskite solar cells may provide a reliable royal road for realizing commercial application in exterior building window, with the combination of large-area roll-to-roll printing technique, etc. (C) 2017 Elsevier B.V. All rights reserved.