Solution-synthesized SnO2 nanorod arrays for highly stable and efficient perovskite solar cells

We report a simple and low-cost approach to enhance the longstanding stability of the perovskite solar cell (PSC) through the application of low-temperature grown SnO2 nanorod (NR) arrays. SnO2 NR arrays were fabricated by an aqueous synthesis method in the presence of hydrochloric acid and using thin compact SnO2 as seeds. The influence of HCI concentration on the photovoltaic (PV) performance of the SnO2 NR array based PSC device was investigated. The formed crystalline SnO2 nanorods with square transversal-sections were oriented on the FTO facets in a well-defined and perpendicular fashion at an optimal HC1 concentration. The optimized width and length for Sn(O2 )nanorods were 30 nm and 150 nm, respectively. Consequently, efficient and stable SnO2 nanorod based perovskite devices were obtained with an average power conversion efficiency (PCE) of 16.57%. The SnO2 nanorod array based PSCs demonstrated considerably better ultraviolet (UV) and ambient air stability than the planar SnO2 and notably mesoporous TiO2 solar cells. This paper provides a prospective scheme to grow high-quality three-dimensional SnO2 nanorod arrays for highly stable and efficient PSCs. (C) 2018 Elsevier Ltd. All rights reserved.