Experimental and theoretical investigation of kt 2 and velocity in YbGaN films by DFT

Email: yktr70@akane.waseda.jp.yanagitani@waseda.jp Abstract-GaN films have been attracting attention for hetero-structure field effect transistors with high electron mobility. The piezoelectric effects of GaN act as a key role for the 2DEG confinement. In previous study, our group experimentally discovered that alloying YbN into GaN enhances the electromechanical coupling coefficient $k_{\mathrm{t}}^{2}$ . In this study, we compared the experimental and theoretical values of $k_{\mathrm{t}^{2}}$ and acoustic velocity predicted by DFT.