Fig. 4From: Solution-Processed Cu(In, Ga)(S, Se)2 Nanocrystal as Inorganic Hole-Transporting Material for Efficient and Stable Perovskite Solar CellsTop view SEM image of a CH3NH3PbI3 and b CH3NH3PbI3/CIGSSe deposited on the surface of FTO/bl-TiO2/mp-TiO2. c Cross-sectional SEM structure of FTO/bl-TiO2/mp-TiO2/CH3NH3PbI3/CIGSSeBack to article page