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

Abstract

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.