DOI

This study presents the results of the synthesis, investigation of crystal structures, and luminescent properties of new green-emitting BaBi2−xTbxB2O7 phosphors. Phase analysis was conducted, and the unit cell parameters for all solid solutions were refined. Excitation spectra and photoluminescence spectra of the BaBi2−xTbxB2O7 phosphors were studied. The phosphors emit their strongest light at a wavelength of 545 nm, which is due to the 5D4→7F5 ion transitions. The optimal doping concentration is x = 0.3. The crystal structures of BaBi1.90Tb0.10B2O7, BaBi1.70Tb0.30B2O7 and BaBi1.60Tb0.40B2O7 were refined based on single-crystal X-ray diffraction data, achieving R values of 0.05, 0.04, and 0.06, respectively. An analysis of the occupancy of crystallographic sites by REE3+ atoms in BaBi2−xTbxB2O7 was performed, revealing that Tb3+ atoms occupy the M3 sites. The incorporation of Tb3+ atoms into the crystal structure results in a change in the type of solid solutions. The critical distance between the Tb3+ ions is 10.17 Å for the x = 0.3 solid solution. The identification of the nature of exchange interactions between Tb3+ ions demonstrates that concentration quenching in the BaBi2B2O7:Tb3+ phosphors occurred due to energy transfer among the nearest neighbor ions. Analysis of the crystallographic sites occupied by Tb3+ ions, allowed to conclude that two-dimensional energy migration is realized in the BaBi2B2O7:Tb3+ phosphors. Additionally, an analysis of the compositional deformations and thermal equivalents of the compositional deformations in the BaBi2−xREExB2O7 (REE = Eu3+, Sm3+, Tb3+) borates was conducted. It can be concluded that BaBi2B2O7:Tb3+ is promising green-emitting phosphors for W-LEDs.
Язык оригиналаанглийский
Номер статьи116611
ЖурналOptical Materials
Том159
DOI
СостояниеОпубликовано - 1 фев 2025

ID: 130916551