Fig. 5From: WO3 Nanoparticles or Nanorods Incorporating Cs2CO3/PCBM Buffer Bilayer as Carriers Transporting Materials for Perovskite Solar CellsTop-view SEM images of the perovskite layers deposited a WO3 NL, b WO3 NAs, c WO3 NL/Cs2CO3/PCBM, and d WO3 NAs/Cs2CO3/PCBMBack to article page