Thermal-stability synergy improvement of Sm3+ and Eu3+ in Ca3.6In3.6(PO4)6: the effect of local symmetry. Issue 10 (28th February 2023)

• Record Type: Journal Article
• Authors: Wang, Rong-Rong; Li, Gui-Hua; Cai, Ge-Mei
• Is Part Of: Journal of materials chemistry. Volume 11:Issue 10(2023)
• Page Start: 3616
• Page End: 3625
• Publication Date: 2023-02-28
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc05406j
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : In Ca3.6 In3.6 (PO4 )6, co-doping increased local symmetry and triggered the synergy enhancement of Eu 3+ or Sm 3+ emission in thermal stability. High TQ, good QE and excellent color made these new red phosphors potentially useful in high quality WLEDs. Abstract : The thermal stability of phosphors, particularly for the red component, is a major factor restricting the quality improvement of PC-WLEDs. Numerous researchers have invested considerable time and effort into developing excellent thermally stable red phosphors. Herein, a synergistic strategy of enhancing symmetry based on homogeneity co-doping was proposed to enhance the luminous performance of phosphors. As a typical application case, using Ca3.6 In3.6 (PO4 )6 as a host, a series of single-doped and co-doped Eu 3+, Sm 3+ red phosphors were designed and synthesized. In contrast to single-doped phosphors, Eu 3+, Sm 3+ co-doped phosphors show reinforced UV absorption and improved thermal stability. At room temperature, the fluorescence lifetime of Sm 3+ decreases to a certain extent as the Eu 3+ concentration increases, indicating the energy transfer from Sm 3+ to Eu 3+ . The co-admixture of Eu 3+ and Sm 3+ increased crystal local symmetry, which succeeded in triggering the synergy enhancement of thermal stability for Eu 3+ or Sm 3+ doped phosphors. Moreover, the internal quantum efficiency of Ca3.6 In(1− x − y )3.6 (PO4 )6 :0.05Eu 3+, 0.04Sm 3+ phosphor highly reaches 82.8%. A warm white light-emitting diode based on Ca3.6 In(1− x − y )3.6 (PO4 )6 :0.05Eu 3+, 0.04Sm 3+ with low CCT (4694 K), high Ra (86.9), and CIE chromaticity coordinate (0.3445, 0.3253) was fabricated. The present results expect that Eu 3+, Sm 3+ co-activated Ca3.6 In3.6 (PO4 )6 phosphors are suitable for application in high-power LEDs. Most importantly, this study provides new insight into the relationship between local symmetry and thermal stability and offers a creative strategy for developing high-quality phosphors in the future.