Effects of High Pressure and Thermal Treatments on Photoluminescence Efficiency of CNx Film

Laser induced photoluminescence of carbon nitride films was measured under high pressures up to 24 GPa and after thermal treatment at different temperatures. The experimental results show that both effects of thermal treatment and high pressure induce the decrease of photoluminescence strength, but the former is non-recoverable while the later recoverable after release of pressure to ambient atmosphere. The two kinds of quenching of photoluminescence are attributed to different mechanism. Our results supply a further experimental evidence to support the active PL center model of the undistorted aromatic sp2 cluster with various size and embedded in sp3 bond matrix.