Facile synthesis of a thermally stable Ce³⁺:Y₃Al₅O₁₂phosphor-in-glass for white LEDs

Abstract

a This study outlines a general but convenient approach to the synthesis of Ce 3+ :Y 3 Al 5 O 12 phosphor-inglass (PiG) with a relative low sintering temperature. A comparative study of as-synthesized PiG and glass ceramic prepared by conventional route was carried out to explore the structural, morphological and optical properties. In addition, the effect of phosphor concentration, sintering temperature/time on the luminescence properties was systematically investigated. Notable, we fabricated a high-performance white LED based on PiG with high luminous efficacy ( 125 lmW), low correlated colour temperature (4329 K) and color rendering index of 68. Furthermore, the PiG material demonstrates an excellent thermal stability up to 150 ℃, superior to low thermal stability of conventional Ce 3+ :Y 3 Al 5 O 12 doped silicone. Therefore, the present transparent phosphor glass will have desirable potential for application in the high powered W-LEDs.robust, long-lifetime and environment-friendly features. [1][2][3][4][5][6][7][8][9] Currently, a blue InGaN chip combines with yellow Ce:YAG phosphors mixed with silicone or organic resin is still the dominant technique for fabricating commercial white LEDs. 10,11 Such silicones or organic resins are likely to deteriorate and turn yellow under long-term exposure to high temperature, which is ascribed to its poor thermal conductivity and low thermal stability, leading to the degradation in LE and shifting on chromaticity. 12,13 Therefore, the exploration and development of good thermal-stable carriers for phosphors in the high power WLEDs is urgently necessary.Recently, glass-based encapsulants have been investigated profoundly and broadly for enhancing the thermal and moisture stability of phosphor. Among these, phosphor-in-glass (PiG), dispersing phosphors directly into glass matrices, exhibited its superiority as encapsulant over phosphor-in-silicone (PiS) in terms

Tunable Eu2+ emission in KxNa1−xLuS2 phosphors for white LED application

“…However, many suffer from very low excitation efficiency in near UV part of the spectrum, see for example [22][23][24][25]. Nowadays, the garnets are probably the most widely used [26][27][28][29][30][31][32][33]. Recently, a very interesting group of sulfide-based materials has been given attention as well [34][35][36][37][38][39][40][41][42][43][44][45][46].…”

Glass and Process Development for the Next Generation of Optical Fibers: A Review

“…Dissolution of the nano-/micro-scale crystals or a decrease in the transmission of the resulting glass was reported in [78][79][80][81][82]. For example, a reduction of the crystal size from 18.3 down to 14 µm was reported when melting the batch at 520 • C for 10 min [79]. As explained in [83], an extremely high risk of completely dissolving the nanoscale crystals can occur during the melting.…”

“…However, as explained in [76,77], an insufficient dispersion of the NCs had been obtained using this technique [76]. Dissolution of the nano-/micro-scale crystals or a decrease in the transmission of the resulting glass was reported in [78][79][80][81][82]. For example, a reduction of the crystal size from 18.3 down to 14 µm was reported when melting the batch at 520 • C for 10 min [79].…”

Chromaticity-Tunable and Thermal Stable Phosphor-in-Glass Inorganic Color Converter for High Power Warm w-LEDs

“…In past decades, scientists and engineers have been interested in white light-emitting diodes (w-LEDs) because of their extremely long life and high energy efficiency relative to conventional lighting sources [1,2,3]. Despite the fast progress in developing LED technology, mainstream LED products that combine blue LEDs with a mixture of Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+ ) and organic encapsulation materials still suffer significant technical problems of shifting on chromaticity and degradation in luminous efficacy (LE) caused by the yellowing and aging of silicone or epoxy resin [4,5,6,7].…”