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

LaScO3:xBi(3+),yTb(3+),zEu(3+) (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:xBi(3+),yTb(3+),zEu(3+) 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:xBi(3+),yTb(3+),zEu(3+) 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, LaScO3:0.02Bi(3+),0.05Tb(3+),zEu(3+) and LaScO3:0.02Bi(3+),0.03Eu(3+),yTb(3+). The energy transfer was characterized by decay times of the LaScO3:xBi(3+), yTb(3+), zEu(3+) 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 S-a and S-r 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.