All solid-state solar cells based on CH3NH3PbI3-sensitized TiO2 nanotube arrays.

TiO 2 nanotube arrays (TiO 2 NTAs) were firstly used as photoanode in methylammonium lead iodide (CH 3 NH 3 PbI 3 ) perovskite/TiO 2 NTAs heterojunction solar cell, where CH 3 NH 3 PbI 3 functions as both light absorber and hole conductor. The composition, structure and photoelectrochemical properties of the as-prepared samples were characterized by x-ray diffractometer (XRD), field-emission scanning electron microscope (FE-SEM), ultraviolet-visible (UV–vis) spectrophotometer and electrochemical workstation. The results indicate that the as-prepared CH 3 NH 3 PbI 3 belongs to the cubic crystal system, and TiO 2 NTAs sensitized by 0.3 M CH 3 NH 3 I and PbI 2 exhibit the best photoelectrochemical properties with an open-circuit voltage of 0.422 V and a short-circuit current density of 173.4 μA cm −2 . The EIS result shows that the extremely large resistance at CH 3 NH 3 PbI 3 /FTO interface contributes to the low current density of the perovskite solar cell. [ABSTRACT FROM AUTHOR]