Planar Heterojunction Perovskite Solar Cells with TiO2 Scaffold in Perovskite Film

Abstract TiO 2 nanoparticle is employed as mesoporous scaffold under low temperature in methylammonium lead iodide (MAPbI 3 ) perovskite layer for planar heterojunction solar cells (PH PSCs). It has been found that the high quality perovskite crystalline is obtained by adding TiO 2 nanoparticles into perovskite layer. The incident photon to current conversion efficiency (IPCE) has been significantly improved due to the enhanced light scattering of TiO 2 nanoparticles and efficient electron transport in perovskite layer. Specially, interconnected TiO 2 nanoparticles improves the electron transport property, leading to reducing hysteresis and obtaining the much higher power conversion efficiency (PCE) (12.96%) with V oc  = 0.99 V, J sc  = 22.9 mA/cm 2 and FF = 0.562. This fabrication method is promising for flexible PH PSCs application and reducing the preparation cost.