Synthesis, spectral and surface investigation of NaSrBO₃: Sm³⁺ phosphor for full color down conversion in LEDs

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• 作者：Vinay Kumar^a ; ^b ; ^{vinaykdhiman@yahoo.com} ; ^{vinaykumar@smvdu.ac.in} ; A.K. Bedyal^a ; Shreyas S. Pitale^b ; O.M. Ntwaeaborwa^b ; H.C. Swart^b
• 关键词：Phosphors ; XPS ; ToF SIMS ; Orthoborates ; Luminescence
• 刊名：Journal of Alloys and Compounds
• 出版年：2013
• 出版时间：25 March, 2013
• 年：2013
• 卷：554
• 期：Complete
• 页码：214-220
• 全文大小：1780 K

文摘

Orange-red emitting NaSrBO₃: Sm³⁺ phosphors were prepared by the combustion method using metal nitrates as precursors and urea as fuel. The particle sizes were in the range of 38-43 nm. The monoclinic structure that is in good agreement with the standard NaSrBO₃ was confirmed by X-ray diffraction. Scanning electron microscopy (SEM) indicated that an agglomerated peanut like morphology was obtained. UV-VIS spectrocsopy, photoluminescence (PL) and cathodoluminescence (CL) spectroscopy were utilized to investigate the spectral properties of the phosphor. The chemical states and the distribution of the dopants in the host were analysed with X-ray photoelectron spectroscopy (XPS) and time of flight-secondary ion mass spectroscopy (TOF-SIMS), respectively. Under the excitation of near UV light, NaSrBO₃: Sm³⁺ exhibits the characteristic emissions resulting for the ⁴G_5/2 ¡ú ⁶H_x/2 (x = 5, 7 and 9) transitions of Sm³⁺, with a maximum intensity at 599 nm. In addition, the concentration of Sm³⁺ was varied in order to determine the optimum PL emission intensity. A maximum intensity was obtained from the sample with 2.0 mol % of Sm³⁺. The potential applications of this phosphor, as a down conversion phosphor with an excitation wavelength of 395 nm and good CL intensity, are evaluated for the possible use as a high-color-purity phosphor in light emitting diodes (LEDs) that can fill the 590-600 nm gap and it may also be used as an amber color field emission display (FED) phosphor.