Facile synthesis of photosensitive iron oxide nanorods and their application as UV photodetectors

Iron oxide nanorods (NRs) possess excellent optoelectronic properties leading to potential UV photodetection and other sensing applications. A wet-chemical synthesis method was carried out to synthesize iron oxide NRs, which were then investigated for their physical and chemical properties. X-ray Diffraction (XRD) confirmed the formation of γ-FeOOH/γ-Fe₂O₃/α-FeOOH mixed phases of iron oxide. Transmission electron Microscope (TEM) analysis confirmed an average NR length of ∼ 62 ± 23 nm and average diameter of ∼ 10 ± 3 nm. Magnetic Force Microscopic (MFM) studies confirm the magnetic nature of the sample with magnetization degree of ∼ 76 ± 22°. The bandgap of the as-synthesized NRs was estimated to be 2.06 eV by Ultraviolet-visible (UV) spectroscopy. A thin film of the as-synthesized samples was cast on the screen-printed electrodes for measuring the photocurrent in dark and UV illumination at 365 nm wavelength. The NRs exhibited a quick UV photoresponse and recovery times of ∼ 8 ± 3 s at the minimal applied bias of 0.5 V. The synthesis resulted in iron oxide nanorods with impressive response and recovery times. As compared to existing literature reports, this is the first time undoped and multi-phase oxides of iron have been used for UV photodetection application.