关键词: 荧光粉, 光致发光, Tb³⁺掺杂, Dy³⁺掺杂, 长余辉, 余辉机理模型

Abstract: SrAl₂O₄：x%Tb³⁺(SAO：Tb, x=0.3, 0.5, 1.0, 2.0, 3.0), SrAl₂O₄：1.0%Tb³⁺, y%Dy³⁺(SAO：Tb/Dy, y=0, 0.5, 1.0, 3.0, 5.0) series of residual luminescent materials were synthesized by high temperature solid phase method under air atmosphere. XRD patterns and SEM images show that the SAO：Tb and SAO：Tb/Dy samples are all pure phase. The excitation spectrum, emission spectrum and afterglow attenuation curves of SAO：Tb show that the afterglow performance are best when the doping concentration of Tb³⁺ is x=1.0. Dy³⁺ co-doping experiments were carried out on SrAl₂O₄：1.0%Tb³⁺, the sample with the better afterglow performance. The excitation and emission spectra intensities of SAO：Tb/Dy series samples indicate that there may be exist energy transfer (ET) processes in SAO：Tb/Dy phosphors. The afterglow attenuation curves further verify that the number of traps increase after Dy³⁺ co-doping. Comparision with thermoluminescence curves intensities between SAO：Tb and SAO：Tb/Dy indicate that the number of traps in this material increases due to the inclusion of Dy³⁺, at the same time, after co-doping with Dy³⁺, the energy range between trap 1 and trap 2 is reduced, which makes it easier to release more electrons. Combined with the thermos luminescence curve and the luminaire surface temperature, the electron release temperature of SAO：Tb phosphor trap 2 decrease from 117 ℃ to 97 ℃ while Dy³⁺ are incorporated, so that all the trapped electrons can released rely on the heat from the luminaire, thereby converting some of the thermal radiation into visible light, therefore, the SAO：Tb/Dy phosphors are not only free from the reducing atmosphere in preparation process, but also have potential application value in reducing lighting energy consumption and reducing the thermal radiation of lamp source.

Key words: phosphor, photoluminescence, Tb³⁺ doping, Dy³⁺ doping, long afterglow, afterglow mechanism model