Near infrared to vacuum ultraviolet optical properties of GdScO3.

Generalized ellipsometry measurements are used to extract the complex dielectric function (ε = ε 1 + i ε 2) spectra of GdScO3 single crystals over the 0.7–8.5 eV photon energy range. GdScO3 is a wide bandgap semiconductor with a high dielectric constant, and potential applications include replacing SiO2 in silicon-based transistors and as an epitaxial substrate for thin film growth. This work presents the anisotropic optical properties for electric fields oscillating parallel to the a-, b-, and c-crystallographic axes. A direct bandgap is identified at 6.44 eV along the direction parallel to the a-axis, with additional critical points observed at 6.74 and 7.42 eV in the same direction. Additional above gap critical point transitions are found at 6.72, 7.31, and 7.96 along the direction parallel to the b-axis and 6.83 and 8.00 eV along the direction parallel to the c-axis. [ABSTRACT FROM AUTHOR]