Study of defects in CVD and ultradisperse diamond

Abstract

Characterization of defects in chemical vapor deposition (CVD) and detonation synthesis ultradisperse diamond (UDD) is reported. Electron Spin Resonance, Raman, and photothermal deflection spectroscopies show that sp(2)-bonded carbon is a dominant defect in UDD diamond. Although UDD was made from trinitrotoluene, no substitutional nitrogen was detected. Photoluminescence (PL) from CVD films showed narrow lines at 1.68, 1.945 and 2.156 eV, in addition to broad red and green bands, while only a blue band was observed in UDD samples. On the basis of PL excitation measurements, the green band in CVD diamond is attributed to donor-acceptor pair recombination. On the basis of a spatial variation of PL intensity in CVD films, the incorporation mechanism for silicon, nitrogen, and boron atoms is discussed. The Manuscript Prime Novelty statement: It is shown that sp(2) carbon is a dominant defect in diamond obtained by detonation technique from trinitrotoluene, while no substitutional nitrogen was detected. The green band in CVD diamond is proved to originate from donor-acceptor pair recombination. (C) 1999 Elsevier Science S.A. All rights reserved.