Fig. 8From: WO3 Nanoparticles or Nanorods Incorporating Cs2CO3/PCBM Buffer Bilayer as Carriers Transporting Materials for Perovskite Solar Cells a Transmission spectra of different WO3 without and with Cs2CO3/PCBM bilayer. b Absorption spectra of the perovskite on WO3 NL without and with Cs2CO3/PCBM bilayer. c PL spectra of the perovskite on FTO, WO3 NL, and WO3 NL/Cs2CO3/PCBMBack to article page