Infrared dielectric functions and Brillouin zone center phonons of $\alpha$-Ga${}_2$O${}_3$ compared to $\alpha$-Al${}_2$O${}_3$

Megan Stokey, Rafal Korlacki, Matthew Hilfiker +11

We determine the anisotropic dielectric functions of rhombohedral $\alpha$-Ga${}_2$O${}_3$ by far-infrared and infrared generalized spectroscopic ellipsometry and derive all transverse opti…