Photoluminescence of MCM meso-porous materials

Different photoluminescence (PL) techniques have been used to study the emission of light from MCM-41 and MCM-48. It was found that the intensity of PL is enhanced after rapid thermal annealing (RTA). This enhancement is explained by the generation of the oxygen-related defects according to the surface properties. Through the analysis of PL with RTA and photoluminescence excitation (PLE), we suggest that the NBOHC and the twofold coordinated silicon centers are responsible for the red and blue–green PL of MCM meso-porous materials, respectively. The PL intensity in MCM meso-porous materials degrades with time during photoexcitation. The dominant mechanism of PL degradation involves the formation of the chemisorbed oxygen-related complexes on the surface, which are adsorbed onto the surface and act as an efficient quencher of PL.