White light emission from radical carbonyl-terminations in Al2O3-SiO2 porous glasses with high luminescence quantum efficiencies

Development of white phosphors with highly emissive, stable, and less toxic characteristics has been important for display and lighting technology. In this letter, it is shown that sol-gel-derived glasses of aluminosilicate composition, followed by a heat treatment in air at low temperatures around 500 degreesC, exhibit two intense, visible photoluminescence bands: One is due to point defects in these glasses and the other comes from radical carbonyl-terminations on the surface of pores. The photoluminescence provides a white light with high luminescence quantum efficiency (similar to66.5%) under long-wavelength ultraviolet excitation. (C) 2003 American Institute of Physics.