A tunable warm-white-light Sr3Gd(PO4)3:Eu2+,Mn2 phosphor system for LED-based solid-state lighting

A novel tunable full-color-emitting Sr3Gd(PO4)(3):Eu2+,Mn2+ phosphor system was successfully developed. Its excitation wavelength ranging from 230 to 450 nm fits well with the characteristic emission of UV light-emitting diode (LED) chips. The color emission of these phosphors can be tuned across almost the entire visible light spectrum resulting in white light emission with varied hue and correlated color temperature (CCT) by varying the molar ratios of Eu2+ and Mn2+. Moreover, the efficient energy transfer from Eu2+ to Mn2+ was demonstrated via a dipole-quadrupole mechanism by the luminescence spectra and the fluorescence decay dynamics based on the Inokuti-Hirayama theoretical model. These results indicate that the developed phosphor may be promising as a single-component white-light-emitting phosphor for white LEDs.