Effect of Si–N substituting for Al–O bonds on luminescence Sr3AlO4F:Ce3+ phosphor

Cerium-doped Sr3(Al1−x,Six)O4−xNxF oxynitride phosphors with different x values were synthesized by solid-state reaction. The structure and optical properties of these phosphors were investigated by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and photoluminescence (PL) spectra. The XRD results showed that Si–N substitution for Al–O did not change the structure of Sr3AlO4F host and there was no impurity for x < 0.6. With the increasing of x values, the absorption of phosphors at the blue region was enhanced and the emitting band varied from 519 to 529 nm under the 460 nm blue light excitation. The red shift of the emission band was associated with an increase in the crystal-field splitting and the covalence, which arose from the incorporation of N. Moreover, the incorporation of N also improved the thermal quenching properties and the external quantum efficiency with a maximum value up to 43.3%, indicating that this phosphor is a promising candidate for white LEDs application.

Emission spectra of Sr2.975(Al0.6,Si0.4)O3.6N0.4F: 0.025Ce3+ measured at different temperatures (Inset: the thermal stability of Sr3(Al1−x,Six)O4−xNxF: Ce3+ with different x values)Figure optionsDownload full-size imageDownload as PowerPoint slide