Aluminate glass based phosphors for LED applications

Aluminate glasses are transparent in IR, UV and vis, and represent an ideal host matrix for optically active dopants. Due to their lower phonon energies in comparison to silicate glasses, non-radiative transitions are suppressed and high efficiency of luminescence is expected. We present a summary of the most important results of a study of luminescence properties of aluminate glasses prepared in the form of microspheres by flame synthesis in binary and ternary systems Al2O3–RE2O3–(SiO2), RE = Y, Yb, doped with optically active elements, (Er, Ce). The influence composition and crystallization of the host glass on luminescence was studied. The glasses were crystallized under controlled conditions, and the influence of phase composition (glass-to-crystalline phase ratio, fraction of various crystalline phases) on wavelength and intensity of luminescence was studied. Case studies of various systems revealed the luminescence intensities can be efficiently tuned by controlled crystallization of the host glass.