Inverted planar heterojunction solar cells (iPHSCs) were fabricated with novel spiro-bifluorene (CF-Sp-BTh) based hole transport material (HTM) and graphene oxide (GO) modified perovskite (CH3NH3PbI3) as sensitizer. CF-Sp-BTh exhibited relatively high hole mobility and favorable HOMO level with respect to the valence band of CH3NH3PbI3. iPHSC using CF-Sp-BTh HTM and GO (0.5 wt%)-CH3NH3PbI3 achieved the power conversion efficiency (PCE) of similar to 14.28%, with open circuit voltage (V-OC) of similar to 1.07 V and a short circuit current density (J(SC)) of similar to 18.82 mA/cm(2). The photovoltaic performance of FTO/CF-Sp-BTh/GO- (0.5 wt%)-CH3NH3PbI3/PC61BM/Au was higher compared to pristine CH3NH3PbI3 and other GO-CH3NH3PbI3 hybrid based devices. The photoluminescence decay and electrochemical impedance spectra confirmed an enhanced charge separation and retarded charge recombination of GO-CH3NH3PbI3 hybrid based iPHSCs. (C) 2019 Elsevier Ltd. All rights reserved.