Nanoparticles Arrays Ultraviolet-A Detector With Au Schottky Contact

We have demonstrated the synthesis of TiO₂ nanoparticles (NPs) arrays on SiO_x thin film using the glancing angle deposition technique. The deposited TiO₂ NPs are 2-12 nm in size and have a density of ~2 × 10¹² cm^-2. The X-ray diffraction depicted that the TiO₂ NPs are polycrystalline. An optical absorption measurement shows the maximum efficiency lies between 310 and 320 nm. The photoluminescence emission has been observed at 3.28 eV (~378 nm) from TiO₂ NPs. The Au/TiO₂ NPs Schottky detector possesses a high ideality factor (11.4). The device has cutoff at 500 nm and maximum responsivity (0.05 A/W), external quantum efficiency (~16%) at 378 nm. Under white light ON/OFF switching irradiation, the device current is increased from 1.9 to 38 nA and vice versa with a rise time of 1 s and decay time of 0.9 s.