Infrared spectroscopy of ZnSiN2 single-crystalline films on r-sapphire

Abstract

This letter presents a study of optical phonon modes of single-crystalline orthorhombic ZnSiN 2 semiconductor epitaxially deposited on r-sapphire. An epitaxial relationship for ZnSiN 2 film was found from x-ray diffraction to be (0k0) ZnSiN 2 ‖(10 1̄2) Al 2 O 3 and [100] ZnSiN 2 ‖(12̄10) Al 2 O 3 . Six B 1 optical modes were revealed in 400–1000 cm−1 range in s-polarized infrared reflectance spectra. This is consistent with the analysis of the phonon symmetry and selection rules presented. The frequencies of the transversal and longitudinal components, phonon damping, and oscillator strengths of the B 1 phonons as well as high frequency dielectric constant ε ∞xx of the orthorhombic ZnSiN 2 were determined.