Single Vs Mixed Organic Cation for Low Temperature Processed Perovskite Solar Cells

The present work reports a comparative study between single and mixed organic cation based MAPbI(3) and MA(0.6)FA(0.4)PbI(3) perovskite devices fabricated in conjunction with low temperature processed (< 150 degrees C) ZnO electron transport layers. MA(0.6)FA(0.4)PbI(3) perovskite devices demonstrate 37% higher power conversion efficiency compared to MAPbI(3) perovskite devices developed on the ZnO ETL. In addition, MA(0.6)FA(0.4)PbI(3) devices exhibit very low photocurrent hysteresis and they are three-fold more stable than conventional MAPbI(3) PSCs (perovskite solar cells). An in- depth analysis on the charge transport properties in both fresh and aged devices has been carried out using electrochemical impedance spectroscopy analysis to comprehend the enhanced device stability of the mixed perovskite devices developed on the ZnO ETL. The study also investigates into the interfacial charge transfer characteristics associated with the ZnO/mixed organic cation perovskite interface and concomitant influence on the inherent electronic properties. (C) 2016 Elsevier Ltd. All rights reserved.