Thermoluminescence properties of nitrogen containing chemical vapour deposited diamond films

The behaviour of centres due to nitrogen impurities introduced during the g rowth process into the chemical vapour deposited (CVD) diamond lattice is r eported for the first time by thermoluminescence (TL) studies between 300 a nd 670 K after 200-400 nm ultraviolet (deuterium lamp) illumination at 300 K (RT) in air. TL curves exhibit some glow peaks at 490, 520 and 620 K char acterized by activation energies of approximately 1.2, 1.4 and 1.9 eV, resp ectively. Spectral analysis of these peaks which reveals some differences d ue to nitrogen content in the films shows well defined emission bands and i nteresting features leading to a better knowledge of the broad red photolum inescence (PL) band observed in our films. Nitrogen addition during the gro wth of the CVD material leads to the quenching of both of the 1.68 eV line related to Si centre and the broad green band centred at 2.25 eV which were observed for the high quality film. (C) 2001 Elsevier Science B.V. All rig hts reserved.