Tailoring the optical and electrical behavior of Cu_2O/ZnO heterojunction by varying the Zn~(2+) ion concentration for solar-cell applications

摘要

Heterojunctions made from metal oxide semiconductors are of great interest due to their harmless non-toxic property, enormous availability, and chemically stable nature. In this work, we report the fabrication of Cu_2O/ZnO heterojunction by deposition of p-type Cu_2O followed by n-type ZnO via an inexpensive spin coating method at ambient conditions. This report focuses on the study of the properties of Cu_2O/ZnO heterojunction thin films with different precursor concentrations of ZnO (0.05 M, 0.1 M, 0.15 M, 0.2 M, and 0.25 M). The structural, morphological, optical, and electrical properties are performed for different compositions. The band gap of all Cu_2O/ZnO heterojunction thin films ranges between 1.86 eV and 2.02 eV. The Ⅳ characteristics confirm p-n photoactive heterojunction behavior for all the samples with increased current density for lower Zn~(2+) ion concentration.