Low temperature processed ternary oxide as an electron transport layer for efficient and stable perovskite solar cells

Abstract

In this paper, high efficient and stable planar perovskite solar cells (PKSCs) have been designed and fabricated via employing high transparent Mg-doped ZnO films with excellent electron transport ability as a novel class of electron transport layers (ETLs). Due to the optimized band alignment by Mg doping, the photogenerated electron injection and charge extraction from the perovskite film to ETL have been facilitated effectively and the planar PKSC based on 2% Mg-doped ZnO and MAPbI3 yields the maximum power conversion efficiency (PCE) of up to 16.74%. Meanwhile, a higher PCE of 17.85% through a phenyl C60 butyric acid methyl ester (PCBM) interfacial layer between the 2% Mg-doped ZnO and perovksite layer has been achieved for the first time. Moreover, the PKSCs with 2% Mg-doped ZnO/PCBM composite ETLs also demonstrate outstanding long term device stability and up to 91% of original PCE of the PKSCs, which can be retained even after exposure in ambient conditions over three-months.