UV-activated heterojunction in BaTiO3 decorated ZnO nanorods for faster and more efficient photodetector

This study explores the improved ultraviolet (UV) photodetection performance of ZnO nanorods (ZnO NRs) decorated with BaTiO₃ nanoparticles (BT NPs) synthesized using a novel vapor-thermal method (VTM) leading to the formation of a heterojunction upon UV activation that enhances charge separation and reduces charge carrier’s recombination. Initially, ZnO NRs were prepared via a hydrothermal method followed by decoration with BT NPs using the innovative VTM process. To elucidate the morphology and composition of the BT-decorated ZnO NRs, a comprehensive characterization was performed using various techniques, including field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Photoluminescence (PL) and diffuse reflectance spectroscopy (DRS) are employed to study electronic band structure of the BT decorated and undecorated samples. The BT nanoparticle-decorated ZnO NRs exhibited a higher photodetection performance compared to bare ZnO NRs under 365 nm UV light illumination. This improvement is manifested by a lower dark current, a faster rise time (from 2 s to 0.75 s), a shorter decay time (from 46 s to 0.96 s), and higher sensitivity (from 57 to 135). These findings demonstrate the promising potential of the BT nanoparticle-decorated ZnO NRs for application in high-performance UV photodetectors.