Fig. 1From: Enhancement of Perovskite Solar Cells Efficiency using N-Doped TiO2 Nanorod Arrays as Electron Transfer Layer a PCE of solar cells dependence on nominal N doping contents. The data were obtained from 20 pieces of devices for each of conditions. b I–V curves of best performance solar cells based on un-doped TiO2 and 1% N-TiO2 NRsBack to article page