Abstract: 0.5Al₂O₃-0.5P₂O₅-100SiO₂ gels containing organic group (OC₂H₅) were synthesized through partial hydrolysis of alkoxide.
The gels were calcined at 300～700℃ in N₂ atmosphere, in which－OC₂H₅ was carbonized to form carbon nanoparticles with
various sizes. Their absorption and photoluminescence spectra were measured. The absorption edge shifts to the higher-energy side as the
size of the carbon particle decreases. This phenomenon was interpreted in terms of a quantum confinement effect of electron and hole in the
carbon nanoparticles. The gel glasses doped with carbon nanoparticles show a strong and broad room-temperature photoluminescence with a peak
located around 586nm under the excitation of 532nm line of a Nd:YAG laser. The position of photoluminescence peaks shifts hardly with changing
the size of carbon nanoparticles. The photoluminescence spectra are originated from the surface of carbon nanoparticles or interfacial
layer between it and gel matrix. The carbon nanoparticles are amorphous carbon nanoparticle in the gel glasses by the X-ray diffraction,
high-resolution transmission electron microscopy and Raman spectra.

Key words: C/0.5Al₂O₃-0.5P₂O₅-100SiO₂ gel glasses, red photoluminescence, absorption spectra