KYW2O8:Eu3+ – A closer look on its photoluminescence and structure

The crystal structure and luminescence quenching of poly- and single-crystalline KYW2O8:Tb3+

“…The data sets showed C-centered monoclinic lattices and the systematic extinctions were compatible with space group C2/c, similar to our previous studies on europium-substituted samples [10]. The atomic positions of KY 0.913 Eu 0.087 W 2 O 8 [10] were taken as starting values and the three structures were refined with anisotropic displacement parameters for all atoms with SHELXL-97 (full-matrix least-squares on F 0 2 ) [15,16].…”

“…The atomic positions of KY 0.913 Eu 0.087 W 2 O 8 [10] were taken as starting values and the three structures were refined with anisotropic displacement parameters for all atoms with SHELXL-97 (full-matrix least-squares on F 0 2 ) [15,16]. For the doped crystals always one of the 4e sites was refined with Y/Tb mixing, leading to the compositions listed in Table 1 Tables 2 and 3.…”

“…Furthermore, KYW 2 O 8 was studied with europium as a radiation converter in LEDs [10]. Especially for laser applications the yttrium site is partly replaced by ytterbium or erbium [11,12].…”

“…To our surprise, terbium was not studied in this host so far, even though it is an interesting candidate for efficient luminescence due to its small multi-phonon relaxation [13]. In particular, the doping of a low phonon host material like the double tungstate KYW 2 O 8 by Tb 3 þ shall result into efficient green emitting materials [5,10] suitable for dedicated investigations of the luminescence of the 4f-4f levels of Tb 3 þ . Therefore, the present work deals with the optical properties and the structure of potassium yttrium double tungstate doped with trivalent terbium as a function of different doping concentrations in a temperature range from 100 to 500 K: results are presented for single crystals and powders.…”

Synthesis and luminescence characterization of Eu3+-activated Na3La8V3O21 as a red-emitting phosphor

“…This attributes to the position of the 4f electrons of RE doped in a compound [2][3][4][5][6]. Among all the RE ions, Eu 3 þ is one of the most popular ions for its efficient f-f transitions in red-emitting wavelength region, which has been widely investigated in many hosts such as molybdates [7,8], tungstates [9], phosphate [10], vanadates [11,12], etc.…”