A novel Eu-dependent G-La2Si2O7 single matrix phosphor for white light-emitting diodes

A novel G-La2Si2O7: Eu phosphor has been synthesized through SiC-reduction assisted with sol-gel method. Divalent Eu2+ and trivalent Eu3+ luminescent centers coexist in G-La2Si2O7: Eu lattice. Furthermore, two types of Eu2+ luminescent centers exist in G-La2Si2O7: Eu lattice, labeled as Eu1 and Eu2,...

Full description

Saved in:
Bibliographic Details
Published inCeramics international Vol. 47; no. 19; pp. 27571 - 27576
Main Authors Huang, Jinlong, Wan, Jieqiong, Li, Yue, Li, Yan, Wu, Xiaohan, Zhang, Wenqi
Format Journal Article
LanguageEnglish
Published Elsevier Ltd 01.10.2021
Subjects
Emission regulation
Mixed valence
Phosphor
WLEDs
WLEDs
Mixed valence
Emission regulation
Phosphor
Online AccessGet full text

Cover

More Information
Summary:A novel G-La2Si2O7: Eu phosphor has been synthesized through SiC-reduction assisted with sol-gel method. Divalent Eu2+ and trivalent Eu3+ luminescent centers coexist in G-La2Si2O7: Eu lattice. Furthermore, two types of Eu2+ luminescent centers exist in G-La2Si2O7: Eu lattice, labeled as Eu1 and Eu2, arising from two La3+ crystallographic sites in G-La2Si2O7 host. Eu1 represents blue band emission while Eu2 shows green-yellow emission. Eu2+ selective occupation introduces Eu2+ large-scale blue-yellow regulation. Eu3+ shows typical red sharp line emission mainly located at 593 nm and 611 nm assigned to 5D0→7FJ (J = 1, 2) transitions. The luminescence process in G-La2Si2O7: Eu is discussed in details. Energy transfer processes from Eu3+ to Eu1 and Eu2, Eu1 to Eu2 occurs in G-La2Si2O7: Eu lattice. The influence of Eu dopant concentration is explored. As Eu increases, the dominant emission changes from Eu2+ to Eu3+. The coexistence of Eu1, Eu2 and Eu3+ brings G-La2Si2O7: Eu blue to red regulation. Fixing Eu doping at 0.5%, G-La1.99Si2O7: 0.01Eu sample shows a single-phased white light-emitting phosphor. At ultraviolet light 254 nm excitation, the emission spectrum approximate to full spectrum with a high rendering index of Ra = 91 is obtained using La1.99Si2O7: 0.01Eu sample at 254 nm excitation. Besides, G-La2Si2O7: Eu represents a good fluorescent thermal stability with luminous intensity keeping 80% (160 °C) of that at room temperature (30 °C), indicating G-La2Si2O7: Eu is a great potential single-matrix candidate in nUV-chip WLEDs.
ISSN:0272-8842
1873-3956
DOI:10.1016/j.ceramint.2021.06.181