Highly sensitive fast-response UV photodiode fabricated from rutile TiO sub(2) nanorod array on silicon substrate

An ultraviolet photodiode based on rutile TiO sub(2) nanorods, which were grown on p-type Si substrate seeded with a TiO sub(2) layer, was synthesized by radiofrequency reactive magnetron sputtering. Chemical bath deposition was performed to grow rutile TiO sub(2) nanorods. X-ray diffraction and field emission-scanning electron microscopy were conducted to determine the structural and optical properties of the sample. The synthesized TiO sub(2) nanorods exhibited tetragonal rutile structure. The device showed 3.79 x 10 super(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 super(-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 super(2)) at 5 V bias voltage.