Fig. 6From: WO3 Nanoparticles or Nanorods Incorporating Cs2CO3/PCBM Buffer Bilayer as Carriers Transporting Materials for Perovskite Solar CellsAFM topographic and 3D images of a, d bare FTO, b, e FTO/WO3 NL, and c, f FTO/WO3 NL/Cs2CO3/PCBM. The corresponding R a values of different films are also includedBack to article page