Planar Heterojunction Perovskite Solar Cells with TiO₂ Scaffold in Perovskite Film

TiO₂ nanoparticle is employed as mesoporous scaffold under low temperature in methylammonium lead iodide (MAPbI₃) perovskite layer for planar heterojunction solar cells (PH PSCs). It has been found that the high quality perovskite crystalline is obtained by adding TiO₂ nanoparticles into perovskite layer. The incident photon to current conversion efficiency (IPCE) has been significantly improved due to the enhanced light scattering of TiO₂ nanoparticles and efficient electron transport in perovskite layer. Specially, interconnected TiO₂ 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/cm² and FF = 0.562. This fabrication method is promising for flexible PH PSCs application and reducing the preparation cost.