Photodetectors based on one-dimensional structures have recently attracted great interest due to their high surface-to-volume ratio and light-trapping efficiency. In this study, a self-powered photodetector based on vertically aligned WO₃ nanorod with SiO₂ as an interfacial layer has been fabricated using glancing angle deposition. Scanning electron microscope (SEM) analysis confirms the successful growth of WO₃ nanorod and SiO₂ thin film with a thickness of 125nm and 70nm, respectively. The devices optical properties were also analysed using UV-visible spectroscopy, which revealed a wide bandgap and an intense absorption peak in the ultraviolet region. The electrical analysis showed a nonlinear rectifying current-voltage behaviour with high photosensitivity. Additionally, the photodetector exhibits a fast response of 0.31s rise time and 0.32s fall time at 0V. Moreover, the devices possess a high detectivity and a responsivity of 0.68mA/W. Thus, the obtained finding reveals a potential candidate for self-powered photodetector application.

Gadolinium oxide nanorod (Gd₂O₃ NR) was fabricated on an n-type silicon substrate by catalyst-free glancing angle deposition (GLAD) technique. The as-grown sample was annealed at 500 °C to investigate the impact of annealing on structure and optical properties. XRD analysis reveals an improvement in the crystal structure after annealing. Field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray (EDX) confirm the successful growth of vertically aligned Gd₂O₃ NR with the presence of Gd, O, and Si. Transmission electron microscope (TEM) showed the crystalline nature of the grown Gd₂O₃ NR. Finally, UV–vis spectroscopy was performed to study the optical properties. A significant enhancement in the photon absorption (200–300 nm) was observed, which can be attributed to increased grain size, improved crystallinity, and large generation of electron–hole pairs. In addition, the Tauc plot showed a decrease in the bandgap from 5.05 eV to 4.98 eV after annealing at 500 °C.

Graphene oxide (GO) has gained significant attention in recent years due to its exceptional properties and wide range of applications. This study investigates the development of gas sensors based on reduced graphene oxide (rGO) for effective real-time monitoring of gas concentrations. The GO was produced using a modified Hummers’ method and then reduced using tea leaf extracts at different concentrations. The structure of rGO was confirmed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Raman spectroscopy. UV-visible spectroscopy analysis revealed a decrease in the bandgap of rGO with increasing concentrations of tea leaf extract. The gas sensors fabricated with the synthesized rGO were tested with methanol and ethanol, two common volatile organic compounds, demonstrating a fast response and recovery time. In addition, an analog front-end circuit was developed for the sensor exhibiting the highest sensitivity, enabling real-time monitoring of gas concentrations. These results suggest that rGO, reduced using green synthesis methods, holds significant promise for high-performance gas-sensing applications.