Synthesis and Luminescence Properties of Green-to-Red Color-Tunable Upconverting K2Gd(PO4)(WO4):Yb3+,Tb3+,Eu3+ Phosphors

Scientists are increasingly interested in new inorganic luminescence materials that could be excited with near-infrared (NIR) radiation. These can used as luminescent thermometers, bio-imaging agents, anti-counterfeiting pigments, etc. In this manuscript, we report the synthesis and investigation of optical properties two series K2Gd(PO4)(WO4):20%Tb3+ (KGPW): first, KGPW:20%Tb3+ doped 1–20% Eu3+, second, KGPW:10%Yb3+,20%Tb3+ Eu3+. The phase-pure specimens were prepared using a solid-state method. Down-shifting upconversion studies have been performed 340 980 nm excitation, respectively. For emission luminescence, Yb3+ ions sensitizers KGPW phosphors. these phosphors, absorb radiation transfer energy to Tb3+ ions. At his point, either emit themselves or part all their Eu3+ It was observed color synthesized phosphors successfully tuned from green red by varying Tb/Eu concentration ratio regardless excitation. Such change proves one material (KGPW) provide three colors (i.e., green, orange, red). Herein, properties, such reflection, down-shifting excitation spectra, fluorescence lifetime, thermal quenching, coordinates, quantum efficiency, studied steady-state kinetic spectroscopy.