Enhanced efficiency and stability of fully air-processed TiO2 nanorods array, based perovskite solar cell using commercial available CuSCN and carbon

In this study, commercial available inorganic p-semiconductor CuSCN and carbon was employed in replacing the expensive hole transport materials and noble metal electrode of the traditional perovskite solar cell, respectively. TiO2 compact layer and the mesoporous layer were also replaced by TiO2 nanorod arrays. The fully-air processed perovskite solar cells were easy to fabricate and demonstrated an enhanced efficiency and stability. The introduction of CuSCN improves the current density and the fill factor of the solar cell, thus leads to 29% increase in conversion efficiency. Intensity modulated photovoltage (IMVS) shows that the solar cell with CuSCN has a longer electron life time. Current attenuation curve shows that the current of the solar cell with CuSCN rises quicker and higher than that of the solar cell without CuSCN. The steady-state photoluminescence tests shows that the introduction of CuSCN layer enhances the separation of electrons and holes, thus reducing the recombination of electrons and holes. Electrochemical impedance spectroscopy (EIS) reveals that the solar cell with CuSCN has low transport resistance and high recombination resistance, thus leading to the slower electron recombination rates. In addition, study shows that the use of CuSCN and carbon displays high stability, and both kind of cells keep over 80% of the initial efficiency after 30 days without encapsulation. This method simplifies the perovskite solar cell fabrication process and opens a door toward the cheap, stable and printable solar cell.