Study on luminescent properties of Tb³⁺ and Sm³⁺ co-doped CaSiO₃ phosphors for white light emitting diodes

Abstract

A series of CaSiO 3 :x%Tb 3+ , y%Sm 3+ compounds was synthesized by the conventional solid state reaction. X-ray diffraction, scanning electron microscopy, and energy dispersive x-ray spectroscopy investigations were conducted to determine crystal structure. The photoluminescence (PL) excitation spectrum of Tb 3+ and Sm 3+ doped compounds consists of a series of peaks corresponding to electronic transitions of Tb 3+ and Sm 3+ ions. The wavelength of 375 nm was optimal to excite the luminescence of Tb 3+ /Sm 3+ co-doped compounds. The PL emission spectrum consists of a set of intense lines at wavelengths of 415 nm, 436 nm, 457 nm, 488 nm, 543 nm, 586 nm, and 622 nm, corresponding to Tb 3+ electronic transitions of 5 D , respectively. The PL emission spectrum of the Sm 3+ doped compound has a series of three peaks located at wavelengths of 565 nm, 602 nm, and 648 nm, corresponding to the electronic transitions of Sm 3+ from 4 G 5/2 to 6 H 5/2 , 6 H 7/2 , and 6 H 9/2 , respectively. The energy level diagram was proposed. The lifetime measurements were conducted for all samples and energy transfer process was also examined by this way. The Commission Internationale de I'Eclairage chromaticity coordinates, correlated color temperature, and color rendering index of phosphors were determined and the results indicate that the obtained materials are optimal candidate for white LED applications.

Optical and Dynamic Properties of ZnGa2S4

“…CIE coordinates of phosphor are x = 0.3117 and y = 0.3488. The correlated color temperature (CCT) of ZnGa 2 S 4 was calculated based on the CIE result using McCamy's equation [ 24,25 ] where .…”

The application YAG:Ce3+@SiO2 phosphor for improving color deviation of phosphor-converted light-emitting diode

“…Over the decades, such kind of lighting has immensely advanced, which consists of lumen efficiency, great color rendering index (CRI), as well as various advanced attributes [1]- [3]. The creation of the diodes that generate white light-emitting diode (wLED) involves merging the blue, green, and red chips of light-emitting diode (LED), despite that the foundation of most LED lights is phosphor-converted LEDs (pc-LEDs) thanks to the simplicity, quality along with the low cost of the creation process.…”

Revealing the Pressure-Induced Phase Transformation of Xenotime TbPO4 via In Situ Photoluminescence Spectroscopy

“…The dashed and solid downward arrows represent phonon and photon emission, respectively. Adapted from ref . Copyright 2019 IOP Publishing.…”