Enhancing the Performance of ZnO-Based Photodetectors by Forming ZnO/(Cu:ZnO) Core/Shell Nanorods

ZnO nanomaterials are some of the most excellent candidates for low-cost but high-performance photodetectors, particularly in the UV region. Besides doping, architecting ZnO nanomaterials to extend their application is still attractive for developing low-cost optoelectronic devices. Thereby, this study introduces the innovation of ZnO nanorod-based photodetectors by combining two techniques, which are Cu doping and core/shell structuring. Particularly, the active material (ZnO/(Cu-doped ZnO) core/shell nanorods) was synthesized by a low-cost and easy fabrication process. Our device using the developed core/shell nanorods exhibits the maximum responsivity of ca. 4.5 mA W–1 at 395 nm light exposure, which is nearly 180% higher than that of a device based on Cu-doped ZnO NRs (formed with only the Cu-doping technique). This enhancement responsivity is attributed to the improved charge transport at the interface of the core/shell ZnO/(Cu-doped ZnO) NRs, which pertains to a process that reduces the electron–hole recombination probability, resulting in an improvement in the efficiency of the photodetectors. These outcomes reveal the essential role of core–shell structuring in improving the efficiency of ZnO-based photodetectors. In general, our study of ZnO/(Cu-doped ZnO) core/shell nanorods opens a potential approach for developing better photodetectors.