Pressure-induced luminescence quenching in KY(WO 4 ) 2 :Pr 3+

Abstract The quenching of the red Pr 3+ ( 1 D 2 → 3 H 4 ) luminescence in a single crystal of KY(WO 4 ) 2 doped with Pr 3+ is investigated at room temperature under high hydrostatic pressure. The quenching is ascribed to a pressure-induced downshift of the Pr 3+ → W 6+ metal-to-metal charge transfer (or impurity trapped exciton) state. The concomitant decrease of the 1 D 2 → 3 H 4 emission lifetime is reproduced using a phenomenological model. The fitting allows the determination of the pressure-induced shrinkage of the Pr 3+ (Y 3+ )-W 6+ distance in the crystal. The value is consistent with the quantity previously determined in CaWO 4 by means of X-ray diffraction.