Fabrication of single titanium oxide nanodot ultraviolet sensors by atomic force microscopy nanolithography

•Single titanium oxide nanodot ultraviolet sensors have been fabricated.•Atomic force microscopy nanolithography is utilized for the fabrication.•An ohmic and a Schottky contact sensors have been obtained.•The ohmic contact sensor has a sensitivity of 0.25 and a reset time of 80.5 s.•The Schottky contact sensor has a sensitivity of 320 and a reset time of 1.9 s.

We report on the fabrication of single titanium oxide nanodot (ND) ultraviolet sensors by atomic force microscopy (AFM) nanolithography. A single titanium nanowire is first fabricated by AFM nanomachining and gold contact electrodes are then created by photolithography. By subsequent AFM nano-oxidation, a single titanium oxide ND sensor is produced. Two types of ND sensors, namely ohmic contact and Schottky contact, have been obtained and the sensitivities are around 0.25 and 320, respectively, under ultraviolet illumination. The rise and the reset times of the Schottky contact sensor are also significantly faster.