Investigation of the thermal quenching of two emission centers in Sr9MnLi(PO4)7:Eu2+ using time-resolved technique. Issue 27 (3rd July 2020)

• Record Type: Journal Article
• Authors: Chi, Fengfeng; Dai, Wenjuan; Jiang, Bin; Lou, Bibo; Wei, Xiantao; Li, Bin; Cheng, Jie; Liu, Shengli; Yin, Min
• Is Part Of: Physical chemistry chemical physics. Volume 22:Issue 27(2020)
• Page Start: 15632
• Page End: 15639
• Publication Date: 2020-07-03
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d0cp02544e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The emission spectra of two luminescent centers in Sr9 MnLi(PO4 )7 :Eu 2+ and the corresponding schematic diagrams of luminescence thermal quenching. Abstract : The thermal stability of the phosphors in phosphor-converted light-emitting diodes (LEDs) plays an important role in the practical application of lighting. Herein, the Mn 2+ -based red-emitting phosphors of pure and Eu 2+ -doped Sr9 MnLi(PO4 )7 (SMPO) samples were prepared using the high temperature solid-state reaction method. The crystal field environment around the Mn 2+ ions was analyzed by combining the results of photoluminescence excitation spectroscopy and Tanabe–Sugano diagrams. By comparing the results of X-ray photoelectron spectroscopy, two additional bands centered at about 129.8 eV and 130.7 eV were found in the Eu 2+ -doped sample, which corresponded to the chemical states of P 2p3/2 and P 2p1/2 . Two different sets of emission spectra were observed for Sr9 MnLi(PO4 )7 :5%Eu 2+ (SMPO:Eu 2+ ) on employing the time-resolved technique. The emission peaks centered at 615 nm and 661 nm were attributed to Mn 2+ and Eu 2+ ions, respectively. The thermal quenching behaviors of Eu 2+ and Mn 2+ were investigated in the temperature range of 300–620 K and the thermal quenching mechanisms are given in this work. Systematic research on the luminescent properties of Eu 2+ and Mn 2+ ions in the SMPO:Eu 2+ phosphor contributes to the understanding of the thermal stability and aids in the development of Mn 2+ -based red-emitting phosphors.