Thermal quenching and luminescence lifetime of saturated green Sr1−xEuxGa2S4 phosphors

Due to the lack of efficient green emitting solid state light sources, conversion phosphors emitting saturated green emission are highly interesting, both for display and signalling applications. In this work, we study the luminescence properties of Sr1−xEuxGa2S4 phosphors over a wide dopant concentration range (x = 0.01–0.3), as function of temperature. The phosphors show a saturated green emission over the entire studied range, with a typical peak wavelength around 536 nm and a FWHM of 50 nm. The internal quantum efficiency is 71% for x = 0.04. For this concentration, the emission intensity at 400 K is still 90% of the intensity at room temperature. By measuring both decay and thermal quenching profiles as a function of europium concentration, we were able to explain the emission properties on the basis of the local environment of the europium ions in the lattice.

► Pure, saturated green emission peaking at 536 nm (FWHM of 50 nm).
► Internal quantum efficiency of 71% for Sr0.96Eu0.04Ga2S4.
► 90% of emission intensity maintained at 400 K for Sr0.96Eu0.04Ga2S4.
► Thermal quenching studied as function of europium concentration.
► Decay measurements yield information on the non-radiative decay paths.