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

Abstract

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.