Highly crystalline metal oxide semiconductor electron transport bilayers to improve the interface between the electron transport and active layer in planar perovskite solar cells

Abstract

Abstract In this study, we investigate the influence of a bilayer electron transport included of ZnO/SnO2, ZnO/WO3, and SnO2/WO3 on the interface between electron transport layers (ETLs) and perovskite layers to reduce energy loss in planar perovskite solar cells (P-PSCs). The structural, optical, and electrical properties, as well as the surface morphology, of perovskite thin film on different ETLs were investigated systematically by various characterization techniques. Impedance analysis of charge dynamics with PSC and without on metal oxide (MOs) were also studies. The X-ray diffraction (XRD) study confirmed that the prepared sample had a tetragonal rutile crystal structure for perovskite thin film on different ETLs. UV-visible spectra analysis revealed that perovskite thin films on various ETLs almost identical absorption onset at 752 nm were observed. The photoluminescence (PL) spectra study revealed that perovskite thin film on various ETLs an emissive band peaked at around 781 nm. The emission of the perovskite was quenched by 35.8%, for ZnO/MAPbI3 to 72.8% for ZnO/WO3/MAPbI3 to respectively. I–V studies confirmed that the prepared bilayer and singly layer had a good ohmic contact behavior and the resistivity decreased significantly from 128.87 Ω for WO3 to 112.49 Ω for ZnO/WO3 thin film respectively. These results revealed bilayer electron transport is more charge transfer property and charge collection, also there by suppressing trap-assisted recombination at the P-PSC interface. The overall results suggest that the bilayer of electron transport layers provides an efficient approach for improving the interface and fabricating efficient planar perovskite solar cells.