White Photoluminescence of Mesoporous Silica-carbon Composites

Abstract

We found that mesoporous carbon-silica composites synthesized by tri-constituent co-assembly method exhibit very intense visible photoluminescence excited by low-energy UV light. Now, a class of stable, efficient, inexpensive and less toxic photoluminescent materials which emit white light under long-wavelength UV light is strongly required to replace fluorescent lamps by LED lamps. The composites we synthesized satisfy the required conditions and are the promising materials from the environmental point of view. In this study we tried to control the color of the photoluminescence of the mesoporous carbon-silica composites by changing the synthesis conditions. We also investigated the photoluminescent properties of the graphene-like molecules which were synthesized by fusing pentacenes. Furthermore, we demonstrated in the present investigation that not only the pore-to-pore distance but also the pore diameter of the mesoporous materials having quasi two dimensional hexagonal pore structure can be determined by analyzing the small-angle XRD pattern.