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

This letter presents a study of optical phonon modes of single-crystalline orthorhombic ZnSiN2 semiconductor epitaxially deposited on r-sapphire. An e pitaxial relationship for ZnSiN2 film was found from x-ray diffraction to b e (0k0)(ZnSiN2)parallel to(10 (1) over bar 2)(Al2O3) and [100](ZnSiN2)paral lel to(1 (2) over bar 10)(Al2O3). Six B-1 optical modes were revealed in 40 0-1000 cm(-1) range in s-polarized infrared reflectance spectra. This is co nsistent with the analysis of the phonon symmetry and selection rules prese nted. The frequencies of the transversal and longitudinal components, phono n damping, and oscillator strengths of the B-1 phonons as well as high freq uency dielectric constant epsilon(infinity xx) of the orthorhombic ZnSiN2 w ere determined. (C) 2000 American Institute of Physics. [S0003-6951(00)0091 8-9].