Synthesis and photoluminescence of amorphous AlBCO phosphors

Amorphous and nitrogen-free AlBCO phosphors were synthesized by a sol-gel method. The phase evolution, microstructure and photoluminescent properties of the AlBCO phosphors were discussed. The as-prepared phosphors exhibited a broad emission band in the blue–green region under the excitation of violet irradiation with a wavelength of 370 nm. The sample synthesized at 650 °C for 1 h exhibited the highest photoluminescence intensity and quantum yield. The emission band of the sample prepared with the optimum process can be well fitted with three peaks centered at 412, 450 and 516 nm. The preparation process had great effects on the photoluminescent properties of AlBCO phosphors. The intense emission of AlBCO phosphors was assigned to the photoluminescence of both the BO centers coordinated with the Al–O group and the defect levels of C-doped amorphous Al₂O₃. (paper)