Highly sensitive fast-response UV photodiode fabricated from rutile TiO2 nanorod array on silicon substrate

摘要

An ultraviolet photodiode based on rutile TiO2 nanorods, which were grown on p-type Si substrate seeded with a TiO2 layer, was synthesized by radiofrequency reactive magnetron sputtering. Chemical bath deposition was performed to grow rutile TiO2 nanorods. X-ray diffraction and field emission-scanning electron microscopy were conducted to determine the structural and optical properties of the sample. The synthesized TiO2 nanorods exhibited tetragonal rutile structure. The device showed 3.79 x 10(2) sensitivity when it was exposed to 325 nm light (1.6 mW/cm) at 5 V bias voltage. In addition, the internal gain of the photosensor was 4.792 and the photoresponse peak was 460 mA/W. The photocurrent was 6.09 x 10(-4) A. The response and recovery times of the PD were 50.8 and 57.8 ms, respectively, upon illumination of a pulsed UV light (325 nm, 1.6 mW/cm(2)) at 5V bias voltage. (C) 2014 Elsevier B.V. All rights reserved.