Novel nitrogen-hydrogen defects in CVD diamond

Abstract

Nitrogen-doped CVD diamond treated with electron irradiation and subsequent annealing at temperatures from 860 to 1900 °C was studied using FTIR absorption. It was found that nitrogen impurity produces many novel optical centers active in infrared spectral range. The most prominent of them are ascribed to nitrogen-hydrogen complexes. These centers produce absorption lines at 2827, 2874, 2906, 2949, 2990, 3031, 3107, 3123 and 3310 cm-1. Two characteristic absorptions at wavenumbers 1293 cm-1 and 1341 cm-1 were tentatively ascribed to a modified form of nitrogen A-aggregates. A conclusion has been made that in nitrogen-doped CVD diamonds nitrogen atoms may form nitrogen-hydrogen clusters, which are can be considered as modified A-defects.