Tunable color emission in LaScO₃:Bi³⁺,Tb³⁺,Eu³⁺ phosphor

Abstract

LaScO3:xBi3+,yTb3+,zEu3+ (x = 0 − 0.04, y = 0 − 0.05, z = 0 − 0.05) phosphors were prepared via high‐temperature solid‐state reaction. Phase identification and crystal structures of the LaScO3:xBi3+,yTb3+,zEu3+ phosphors were investigated by X‐ray diffraction (XRD). Crystal structure of phosphors was analyzed by Rietveld refinement and transmission electron microscopy (TEM). The luminescent performance of these trichromatic phosphors is investigated by diffuse reflection spectra and photoluminescence. The phenomenon of energy transfer from Bi3+ and Tb3+ to Eu3+ in LaScO3:xBi3+,yTb3+,zEu3+ phosphors was investigated. By changing the ratio of x, y, and z, trichromatic can be obtained in the LaScO3 host, including red, green, and blue emission with peak centered at 613, 544, and 428 nm, respectively. Therefore, two kinds of white light‐emitting phosphors were obtained, LaScO3:0.02Bi3+,0.05Tb3+,zEu3+ and LaScO3:0.02Bi3+,0.03Eu3+,yTb3+. The energy transfer was characterized by decay times of the LaScO3:xBi3+, yTb3+, zEu3+ phosphors. Moreover absolute internal QY and CIE chromatic coordinates are shown. The potential optical thermometry application of LaScO3:Bi3+,Eu3+ was based on the temperature sensitivity of the fluorescence intensity ratio (FIR). The maximum Sa and Sr are 0.118 K−1 (at 473.15 K) and 0.795% K−1 (at 448.15 K), respectively. Hence, the LaScO3:Bi3+,Eu3+ phosphor is a good material for optical temperature sensing.

Structurally induced tuning of the relative sensitivity of LaScO3:Cr3+ luminescent thermometers by co-doping lanthanide ions

“…In particular, the rich energy level configuration of Nd 3+ prevents a selective excitation of the Cr 3+ ions without exciting Nd 3+ as well. Notably, the energy level diagram of Nd 3+ facilitates the Cr 3+ → Nd 3+ energy transfer, which has been reported by many authors[52]. It is noteworthy that the excitation of Ln 3+ ions in co-doped materials could occur in two ways.…”

“…The octahedra share corners along one crystallographic direction and are tilted towards one another in an angle smaller than 90° (which gives rise to the lower symmetry than the cubic one) [49][50][51]. As reported by Huang et al an increase of the temperature causes the enlargement of the cell parameters manifested as a shift of the diffraction reflection toward smaller angles [52]. This can strongly affect the spectroscopic properties of the Cr 3+ ions as the appearance of the emission spectra of this transition metal ion is sensitive to changes in the crystal field strength.…”

Energy transfer-triggered multicolor emissions in Tb3+/Eu3+-coactivated Y2Mo3O12 negative thermal expansion microparticles for dual-channel tunable luminescent thermometers

“…intensities of Tb 3+ ions with and without adding Eu 3+ ions, respectively). 29,30 As disclosed, the η value is dependent on the doping content and reaches its maximum value of 77.9% when x = 0.09 (see Fig. 3(c)), revealing that the ET between Tb 3+ and Eu 3+ ions is efficient.…”

Utilizing the energy transfer mechanism to realize color tunable luminescence

“…Excited by 332 nm light, the PL spectrum consists of a wide band at 360–700 nm with a maximum value of around 472 nm, which is assigned to the 3 P 1 → 1 S 0 transition of Bi 3+ . 28–30…”

“…Dalton Transactions maximum value of around 472 nm, which is assigned to the 3 P 1 → 1 S 0 transition of Bi 3+ . [28][29][30] Fig. 6b shows the PL emission spectra of SLG:xBi 3+ samples with different Bi 3+ ion concentrations under 332 nm excitation.…”