Performance enhancement of perovskite solar cells by employing TiO2 nanorod arrays decorated with CuInS2 quantum dots.

In this work, TiO2 nanorod arrays (TiO2-NAs) were modified by CuInS2 quantum dots (CuInS2 QDs) on the surface of the nanorods. The resultant TiO2-CuInS2 nanorod arrays (TiO2-CuInS2-NAs) were characterized by UV/Vis spectroscopy, transmission electronic microscopy (TEM), and X-ray diffraction (XRD). The TiO2-CuInS2-NAs were applied as scaffold for the preparation of organic-inorganic hybrid perovskite solar cells. In comparison with the solar cell devices based on TIO2-NAs, a significant improvement in the power conversion efficiency had been achieved and the highest efficiency was obtained as 11.7% (under 100 mW/cm2) through the optimization of the growth time of QDs on nanorods. The improvement of the device performance could be attributed to the assistance of CuInS2 QDs in the light harvesting as well as the facilitation of the electron injection from the perovskite to the TiO2 scaffold.