title: Suitability of surface acoustic wave oscillators fabricated using low temperature-grown AlN films on GaN/sapphire as UV sensors.
abstract: Epitaxial AlN films were prepared on GaN/sapphire using a helicon sputtering system at the low temperature of 300 degrees C. Surface acoustic wave (SAW) devices fabricated on AlN/GaN/sapphire exhibited superior characteristics compared with those made on GaN/sapphire. An oscillator using an AlN/GaN/sapphirebased SAW device is presented. The oscillation frequency decreased when the device was illuminated by ultraviolet (UV) radiation, and the downshift of the oscillation frequency increased with the illuminating UV power density. The results showed that the AlN/GaN/sapphire-layered structure SAW oscillators are suitable for visible blind UV detection and opened up the feasibility of developing remote UV sensors for different ranges of wavelengths on the III-nitrides.
authors.forename: Tzu Chieh
authors.initials: TC
authors.lastname: Chen
authors.forename: Yueh Ting
authors.initials: YT
authors.lastname: Lin
authors.forename: Chung Yi
authors.initials: CY
authors.lastname: Lin
authors.forename: W C
authors.initials: WC
authors.lastname: Chen
authors.forename: Meei Ru
authors.initials: MR
authors.lastname: Chen
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Kao
authors.forename: J I
authors.initials: JI
authors.lastname: Chyi
authors.forename: C H
authors.initials: CH
authors.lastname: Hsu