Preparation and luminescence properties of phosphors of rare earth complexes based on polyoxotungstates

Three new phosphors of rare earth complexes based on polyoxotungstates, K3Cs8[Eu(PW11O39)(2)]center dot 11H(2)O (1), K3Cs8[Sm(PW11O39)(2)]center dot 10H(2)O (2), and K5Cs6[DY(PW11O39)(2)]center dot 15H(2)O (3) have been prepared and characterized. The crystallographic analyses reveal that these compounds consist of two monovacant keggin anions [PW11O39](7-) connected by a rare earth ion in a sandwich structure. The investigations of photoluminescence properties show that phosphor 1 emits strong red light at 614 and 702 nm, 2 emits strong orange-red light at 598.7 nm, and 3 exists two strong emissions at 479 nm (blue) and 574nm (orange). The luminescence properties suggest that the 1 can be applied as the potential red-emitting crystal phosphor, and the 3 may be regarded as a potential white light material for LEDs. (C) 2015 Elsevier Ltd. All rights reserved.