کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10128439 | 1645135 | 2018 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Spectroscopic studies of strong red emitting Sr2SiO4:Eu3+ nanophosphors with high color purity for application in WLED using Judd-Ofelt theory and TL glow curve analysis
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Un-doped and Eu3+ doped Sr2SiO4 nanophosphors were synthesized by self-propagating solution combustion synthesis and are characterised with different material and optical characterisations. X-ray diffraction (XRD) confirmed orthorhombic phase, transmission electron microscopy (TEM) revealed the nanophosphors with irregular shape but crystalline in nature. The photoluminescence (PL) excitation, emission spectra and lifetime are thoroughly discussed. The emission spectra due to the excitation under 393â¯nm showed better asymmetric ratios than the 260â¯nm excitation ensuring better color purity of 97%. The comparative investigations using commission international del'Eclirage (CIE) diagram also established that the color purity of 393â¯nm excitation is superior with CIE co-ordinates (0.66, 0.34) and is close to NTSC standards. The Judd Ofelt (JO) intensity parameters (Ω2andΩ4) were obtained from PL emission spectrum and the JO parameters followed the trend Ω2>Ω4 for all Eu3+ concentration. Asymmetric ratios and JO analysis both indicated that the crystal field is non-centrosymmetric in nature. The radiative properties such as branching ratios, emission cross section, optical gain and gain bandwidth of optimised concentration are calculated. Photoluminescence lifetimes exhibited bi-exponential nature and showed higher lifetime for 393â¯nm excitation. Furthermore, the quenching due to non radiative energy transfer mechanism is dominated by multipole-multipole interaction. All these optical characterisations supported the fact that the nanophosphors excited at 393â¯nm have better pertinence towards display, laser and lighting application. Thermoluminescence (TL) studies of the nanophosphors were carried out. The kinetic parameters are calculated using general order kinetics and are verified by computerised glow curve de-convolution (CGCD). TL emission spectra and contour plots were analysed that further confirmed that the emission resembled the same as PL emission spectra.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Optical Materials - Volume 85, November 2018, Pages 363-372
Journal: Optical Materials - Volume 85, November 2018, Pages 363-372
نویسندگان
C. Manjunath, M.S. Rudresha, R. Hari Krishna, B.M. Nagabhushana, B.M. Walsh, K.R. Nagabhushana, B.S. Panigrahi,