|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|4765697||1362360||2018||7 صفحه PDF||ندارد||دانلود رایگان|
â¢Red phosphors Mg2Al4Si5O18:Mn4+ were synthesized for the first time.â¢This phosphor can be efficiently excited by near-UV/blue light to emit deep red emission.â¢Temperature dependence spectrums are investigated to demonstrate its good thermal stability.â¢The fabrication of red-emitting LED revealed its potential application in WLEDs.
A novel red-emitting phosphor Mg2Al4Si5O18:Mn4+ is successfully synthesized using a solid-state reaction method. Aluminosilicate Mg2Al4Si5O18 of low-symmetry orthorhombic phase contains abundant octahedrons and is suitable for Mn4+ doping. A broad absorption band ranging from 240Â nm to 550Â nm in the ultravioletâvisible spectra corresponds to the photoluminescence excitation spectrum. The emission spectrum from 650Â nm to 750Â nm exhibits a strong emission peak at 680Â nm because of the 2Egâ4A2g transition of Mn4+ ion. The critical distance Rc for concentration quenching is â¼33.3Â Ã , and the energy transfer mechanism is determined to be dipoleâdipole interaction. Luminescence mechanism is analyzed using the energy level diagram of Mn4+ ion. Racha parameters B and C are evaluated and used to discuss the nephelauxetic effect for the Mn4+ ions in the Mg2Al4Si5O18. Temperature-dependent fluorescence test demonstrates the good thermal optical properties of the phosphor. An assembled light-emitting diode (LED) device with efficient luminescence demonstrates its practical use. Results indicate the potential application of the phosphor for white LEDs.
Graphical abstractDownload high-res image (316KB)Download full-size image
Journal: Dyes and Pigments - Volume 148, January 2018, Pages 9-15