Preparation and characterization of rare-earth-ion free and orange yellow oxyfluoride phosphors

Rare-earth-ion free luminescent materials composed of Sr3 − xMxAl0.9In0.1O4F (M = Ca, Ba, 0.1 ≤ x ≤ 0.7) and Sr2.5M0.5Al1 − yInyO4F (0.05 ≤ y ≤ 0.15) oxyfluorides were simply prepared by solid-state method. X-ray diffraction (XRD) patterns of the obtained oxyfluorides are exhibited for indexing peak positions. Dynamic photoluminescence (PL) spectra of defect-induced self-activating Sr2.5Ba0.5Al1 − yInyO4 − αF1 − δ and Sr2.5Ca0.5Al1 − yInyO4 − αF1 − δ oxyfluorides are clearly monitored along with bright orange and yellow emission lights. The relative luminescent intensity and CIE coordinates of the defect-induced Sr3 − xMxAl1 − yInyO4 − αF1 − δ phosphors are measured. These rare-earth-ion free oxyfluoride phosphors excited around 365 nm light will be one of unique luminescent materials in applications of NUV-LED.

► The competent rare-earth free oxyfluoride phosphors are initiated.
► Defect-induced self-activating oxyfluoride phosphor is quite effective to prepare white-emitting light for near-UV LED applications.
► The gradual substitutions of Ca2+ and Ba2+ contents in Sr3Al0.9In0.1O4 − αF1 − δ oxyfluoride hosts are amenable to change desired orange-yellow emissions.