American Institute of Physics Publishing
Visible-light photoresponse of an AlN-based film bulk acoustic wave resonator (FBAR) is demonstrated. It is found that the FBAR exhibits a resonant frequency downshift under purple light illumination and the magnitude of the frequency downshift increases as the power density increases within the range of 5–40 mW/cm2. A resonant frequency downshift of 1313 KHz is observed under 40 mW/cm2 illumination, corresponding to a minimum detection power of 6.09 nW. A sub-bandgap photoresponse of the AlN thin film is proposed to explain this phenomenon.
C.J. Zhou, Y. Yang, Y. Shu, H.L. Cai, T.L. Ren, M. Chan, J. Zhou, H. Jin, S.R. Dong, and C.Y. Yang, “Visible-light photoresponse of AlN-based film bulk acoustic wave resonator,” Applied Physics Letters 102, 191914 (3 pp) (2013). https://doi.org/10.1063/1.4807135