Thermally stable and red emitting bismuth ions sensitized SrGa2O4:Eu3+ phosphors for phosphor converted WLED applications

A series of Bi3+ sensitized SrGa2O4:0.08Eu3+ phosphors have been synthesized by high temperature solid-state reaction method. The structural and surface morphological studies have been characterized by X-ray diffraction, Field emission scanning electron microscopy and Energy dispersive X-ray analysis. The optical and luminescence properties of phosphors are done using UV–Visible absorption spectroscopy, photoluminescence excitation and emission spectra and mechanoluminescence studies. X-ray diffraction analysis shows that the phosphors are single phase with monoclinic structure. The intensity of prominent red emission enhanced with the incorporation of Bi3+ ions in SrGa2O4:0.08Eu3+ phosphors due to the effective energy transfer between Bi3+ and Eu3+ ions. The optimized SrGa2O4:0.08Eu3+,0.05Bi3+ phosphor has excellent thermal stability about 96.7% with an activation energy of 0.253 eV. These phosphors can exhibit better mechanoluminescence properties without any irradiation. The synthesized phosphors can be used in solid state lighting, phosphor converted white light emitting diodes and stress sensing applications etc.