Low-cost fabrication of high-performance p-n heterojunction nanostructures for UV and visible light detection and organic gas sensing

In this study, p-type Cr₂O₃ nanoparticles and n-type ZnO nanowires were successfully synthesized on a glass substrate using the chemical bath and hydrothermal methods. The resulting core-shell ZnO-Cr₂O₃ nanostructures exhibited rectification properties, with an ultra-low leakage current of 37.1 pA at a − 10 V reverse bias. The crystal structure of the Cr₂O₃ nanoparticles and ZnO nanowires was confirmed to be polycrystalline and single-crystalline, respectively, through XRD patterns and HR-TEM analysis. These p-n heterojunction nanostructures displayed exceptional response levels of 9.1 × 10⁵ for UV, 2.6 × 10² for blue light, and 826% for organic gas sensing.