Transparent ZNO/glass surface acoustic wave devices with aluminum doped ZNO electrode

This paper reports the fabrication of transparent SAW resonators using AZO as the transparent electrodes. Transparent SAW resonators exhibited two types of wave modes: Rayleigh and Sezawa waves, and signal amplitudes up to 25 dB were obtained with the transparency above 80%. The series resistance effect of the AZO film electrode on the performance of transparent SAW devices have been systematically investigated and results show that the series resistance should be lower than 10 Ω/sq. Temperature sensing showed the transparent SAW device has a temperature coefficient of frequency of ~45 ppm/K. The transparent devices have also demonstrated their ability to induce a strong acoustic streaming with a streaming velocity up to 2.27 cm/s. This research opened a door for further exploration of the SAW devices in transparent electronics such as transparent microfluidics and sensors.