Zinc stannate nanorod as an electron transporting layer for highly efficient and hysteresis-less perovskite solar cells

Abstract

Careful engineering of the electron transfer layer (ETL) is a promising approach to improve the efficiency of perovskite solar cells (PSCs). In this study, we demonstrate the potential of using zinc stannate (Zn2SnO4, or ZSO from here) as ETL for the fabrication of highly efficient PSCs. ZSO was deposited on top of FTO glass as thin films and nanorod arrays using ultrasonic spray pyrolysis (USP) technique. Optical characterizations reveal that perovskite films deposited on such nanorod arrays of ZSO have a lower transmittance exhibiting better charge extraction properties compared to the planar ZSO thin films. The best ZSO-based device reached a power conversion efficiency (PCE) of 18.24% and a high current density of 23.8 mA/cm2. Moreover, these devices showed a lower hysteresis index in compared to the ZSO planar based devices.