Novel luminescence properties of a-C : H films produced by using an organic source at various substrate temperatures

Hydrogenated amorphous carbon films have been fabricated using an organic c arbon source (xylene), at substrate temperatures 10-300 degrees C in plasma -enhanced chemical vapor deposition (PECVD) system. We found that, the carb on films contain pi-bonded clusters with aromatic units, whose size decreas ed with increasing substrate temperature. For samples deposited at lower su bstrate temperature, several photoluminescence (PL) bands were observed, wh ich we attributed to the recombination through some luminescent centers ass ociated with pi-bonded structures. For samples deposited at higher substrat e temperature, only a single peak with a width greater than the widths of t he PL peaks observed in the lower temperature films, which is similar with that of methane-based a-C:H films. (C) 2000 Elsevier Science B.V. All right s reserved.