A low-temperature processed flower-like TiO2 array as an electron transport layer for high-performance perovskite solar cells

Abstract

As an important portion in perovskite solar cells, an electron transport layer (ETL) is essential for high efficiency perovskite devices. In this work, a flower-like TiO₂ array layer grown on an FTO substrate was prepared by a low-temperature (80 °C) chemical bath deposition (CBD) method. The flower-like TiO₂ layer, which is composed of anatase TiO₂ nanorods, was then utilized as an ETL for perovskite solar cells. As a result, excellent light-harvesting efficiency (LHE) and low recombination of electrons and holes lead to an enhanced power conversion efficiency (PCE, 15.71%) than that of traditional mesoporous TiO₂ layer based perovskite devices (13.25%) with less hysteresis. To the best of our knowledge, it is the highest PCE for all low-temperature processed three-dimensional (3D) TiO₂ ETL based perovskite devices. Moreover, it is proved that our perovskite devices are highly reproducible. This work offers a novel method to achieve all low-temperature processed, reproducible and high-performance perovskite solar cells.