<inline-formula> <tex-math notation="TeX">${\rm TiO}_{2}$ </tex-math></inline-formula> Nanoparticles Arrays Ultraviolet-A Detector With Au Schottky Contact

Abstract

We have demonstrated the synthesis of TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanoparticles (NPs) arrays on SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> thin film using the glancing angle deposition technique. The deposited TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> NPs are 2-12 nm in size and have a density of ~2 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> . The X-ray diffraction depicted that the TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> 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 TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> NPs. The Au/TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> 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.