Optical absorption and cathodoluminescence in homoepitaxially grown CVD diamond films

Abstract

Defect-induced optical absorption in diamond layers, homoepitaxially grown by the chemical vapour deposition technique, is investigated by the use of photothermal deflection spectroscopy (PDS). The measured spectral dependence of the optical absorption coefficient for these layers is compared with the optical absorption in type IIa natural and type Ib synthetic diamond. The measured absorption spectra show the orientation-dependent nitrogen incorporation in the homoepitaxial diamond layers. The orientation-dependent nitrogen incorporation is in agreement with the cathodoluminescence data. The characteristic subgap continuum absorption is observed in both {001} and {110} oriented diamond layers.