Abstract

Alcohol soluble titanium chelate TIPD (titanium (diisopropoxide) bis(2,4-pentanedionate)) was used as electron transporting layer to form an ohmic contact with the negative electrode, aiming to enhance the charge extraction and suppress the charge recombination for high performance CH₃NH₃PbI₃/PCBM-based PHJ perovskite solar cells. The TIPD layer shows excellent suitability to CH₃NH₃PbI₃ perovskite synthesized from different methods. For one-step synthesized CH₃NH₃PbI₃, The power conversion efficiency (PCE) of the device with TIPD buffer reaches 8.75%, with nearly 33% increase in comparison with the device without the buffer layer (6.58%). For two-step synthesized CH₃NH₃PbI₃, an open-circuit voltage (V_oc) of 0.89 V, a short-circuit current density (J_sc) of 22.57 mA/cm², and a fill factor (FF) of 64.5%, corresponding to a PCE of 12.95% for the device with TIPD buffer layer, which is among the best performance reported in literatures for CH₃NH₃PbI₃/PCBM-based PHJ perovskite solar cells.

© 2015 Optical Society of America