Weak piezoelectricity in GaN is a problem in bulk acoustic wave filters and heterostructure field-effect transistors. In this study, enhancement of piezoelectricity in c-axis direction by substituting Yb for Ga was experimentally demonstrated. Thickness extensional mode electromechanical coupling coefficient kt for the YbxGa1-xN films increases with the Yb concentration from x = 0 to 0.3. Yb0.30Ga 0.70N film near the phase boundary exhibited a maximum kt of 3.1%, which is approximately 2.5 times larger than that for a pure GaN.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)