Optical properties of Eu2+-doped KLuS2 phosphor

Pure KLuS2 single crystals doped with divalent europium were synthesized in the form of crystalline hexagonal platelets. UV/Vis absorption and luminescence characteristics were measured in the broad temperature and concentration interval. The band edge of KLuS2 is found at 303 nm, Eu2+ 4f-5d excitation band at 390 nm and Eu2+ emission at 520 nm with submicrosecond decay time. No significant thermal quenching of the Eu2+ emission is observed up to 200 degrees C. Phenomenological modeling and delayed recombination decays measurement are employed to investigate the Eu2+ excited state dynamics. The application potential in white LEDs or X-ray phosphors is discussed. (C) 2013 Elsevier B.V. All rights reserved.