Optical Absorption inn-Type Cubic SiC

Abstract

Nitrogen doping of cubic SiC increases the optical absorption in two regions. The free-carrier intraband absorption has a wavelength dependence of ${\ensuremath{\lambda}}^{2.8}$. An additional narrow band near 3.1 eV is shown to be the direct interband transition from the ${X}_{1c}$ conduction band to the higher ${X}_{3c}$ band. The relationship to Biedermann's work on other SiC polytypes is indicated.