Study on the mechanism of improved luminescence in SrB2Si2O8: Ce3+/Tb3+ phosphor

• Published in: Journal of luminescence Vol. 214; p. 116541
• Main Authors: Yang, Cheng, Liu, Quansheng, Huang, Dexin, Li, Xin, Zhang, Xiyan, Bai, Zhaohui, Wang, Xiaochun, Mi, Xiaoyun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-10-2019
• Subjects: Energy transfer; Luminescence; SrB2Si2O8: Ce3; Tb3; W-LEDs; SrB2Si2O8: Ce3; Tb3; Energy transfer; W-LEDs; Luminescence
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2019.116541

SrB2Si2O8: Tb3+ and SrB2Si2O8: Ce3+, Tb3+ phosphors were synthesized through conventional high temperature solid state reaction method. Under near ultraviolet (NUV) excitation of 377 nm, the emission peaks of the SrB2Si2O8: Tb3+ green phosphor located at 489, 544, 585 and 623 nm corresponding to Tb3+ ions energy level transition of 5D4 excitation state to 7F6, 7F5, 7F4 and 7F3 ground states, respectively. The optimal concentration of Tb3+ ions is 11at.%, and the concentration quenching mechanism can be interpreted by the dipole-quadrupole interaction of Tb3+ ions. For the Sr1-xB2Si2O8: Ce3+, xTb3+ phosphors, the maximum luminescence intensity is 21 times higher than that of the single doped Tb3+, which originates from the energy transfer of Ce3+ to Tb3+ ions. The energy transfer efficiency is calculated to be 79.7%, which is caused by the dipole-dipole resonant type. The CIE coordinates of SrB2Si2O8: Ce3+, Tb3+ phosphors change from blue (0.167, 0.071) to green (0.241, 0.546). When the temperature reaches 210 °C, the luminescence intensity reaches 72.20% of the initial value, indicating that the materials have good thermal stability. The above consequences demonstrate that the SrB2Si2O8: Ce3+, Tb3+ phosphors can be used as a candidate for a promising green luminescent phosphor in ultraviolet excited W-LEDs.
Energy level diagram of energy transfer in the SrB2Si2O8: Ce3+, Tb3+ phosphors; CIE diagram of Ce3+/Tb3+ doped SrB2Si2O8 phosphors. [Display omitted]
•Ce3+, Tb3+ co-doped energy transfer was first proposed in SrB2Si2O8 phosphor.•The energy transfer efficiency of Ce3+ to Tb3+ is as high as 79.7%.•The luminescence intensity of Ce3+, Tb3+ co-doped is 21 times higher than that of single-doped Tb3+.•The energy transfer from Ce3+ to Tb3+ is caused by the resonance of the dipole-dipole.•Ce3+, Tb3+ co-doped SrB2Si2O8 phosphors have potential applications in ultraviolet excited W-LEDs.