Epitaxial rutile TiO2 film based on MgF2 substrate for ultraviolet detector

• TiO2 (110) thin films were fabricated on MgF2 by pulsed laser deposition.
• The TiO2 thin films were high-quality epitaxial rutile phase.
• Interdigitated Ni/TiO2/Ni structure was fabricated.

High-quality epitaxial rutile TiO2 (110) thin films have been fabricated on MgF2 (110) substrates by pulsed laser deposition (PLD). The samples were characterized with respect to their structural, morphological, and optical properties using various methods such as X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy and UV–Vis spectroscopy. The results demonstrated that the synthesized TiO2 thin films were pure rutile phase, untwined (110)-oriented epitaxial thin films. In order to test the UV photoresponse of the epitaxial TiO2 thin film, interdigitated Ni/TiO2/Ni structure was designed and fabricated, which exhibits excellent UV response performance. For the spectral response, a maximum of 4.85 A/W occurs at about 300 nm at 5 V applied bias. The UV detector exhibits excellent photoresponse characteristics with a small bias for detecting application in a wide wavelength range.