Optoelectronic and Electrochemical Properties of Highly Efficient Metal Doped ZnO as Electron Transport Layer in Perovskite Solar Cell /

Abstract

Perovskite solar cells serve a critical role in energy harvesting and meeting the current energy demands. Electron transport layer is responsible for effective transportation of electrons. In this regard, Ca doped zinc oxide at different 1, 2 and 3 wt % of Ca was synthesized and then spin coated in perovskite solar devices as an electron transport layer. Analysis of the Structural properties shows the samples of hexagonal wurtzite ZnO and results were also supported by Raman spectra. Morphological properties of thin films showed uniform films with no defects. The optoelectronic properties revealed that Ca doping caused a shift in the absorption spectra to a more observable range and the band gap has been decreased to 2.8 eV from 3.3 eV calculated using Tauc’s plot. As Ca concentration was increased, more trapping intermediate states were formed enhancing photocatalytic ability and conduction of electrons. According to electrical properties 3 wt% Ca-ZnO show highest conductivity and least resistivity. J-V analysis revealed that Ca doped Zinc Oxide exhibited high current densities and efficiency as compared to undoped zinc oxide The efficiencies of the cells using ETL based on ZnO, undoped ZnO, 1% Ca-ZnO, 2% Ca-ZnO and 3% Ca-ZnO were recorded as 4.93%, 5.96%, 6.88% and 9.79% respectively.