Preparation of Ce:YAG Glass‐Ceramics with Low SiO₂

Abstract

The Ce3+‐doped Y2O3–Al2O3–SiO2 (YAS) bulk glasses with low SiO2 (≤40 mol%) were prepared by flame spray‐quench method and hot press sintering. YAG nanoglass‐ceramics were derived from YAS bulk glass by a controlled crystallization. The differential thermal analysis (DTA) results showed that the glass‐forming ability of YAS system was strongly dependent on SiO2 content and the supercooling degree required for forming YAS glass increased with the decrease of SiO2 content. The YAS glass compositions had been extended to low SiO2 phase region (10–40 mol%) by flame spray‐quench method. The study of crystallization process showed that glass matrixes experienced initially a phase‐separation followed by crystallization during the heat treatment. The phase‐separated grains (100–300 nm) that were composed of YAG nanocrystallites precipitated in the glass matrix. And the intensity of emission spectra increased with the decreasing SiO2 content.

Suppression of phosphor‐glass reactions in YAG:Ce phosphor‐embedded glasses

“…However, the crystallization temperatures are very high (1200°C‐1500°C). Moreover, precipitation of other crystalline phases (eg, yttrium silicates) instead of YAG usually occurs . Phosphor‐embedded glass materials can also be fabricated by mixing phosphor powder with glass powder, following by forming and sintering .…”

Highly thermal-stable warm w-LED based on Ce:YAG PiG stacked with a red phosphor layer

“…This problem becomes more and more serious with increasing the input current necessary to achieve high-power w-LEDs due to the elevation of surrounding temperature. Therefore, inorganic luminescent materials, such as the YAG:Ce 3+ -based transparent ceramics, glass ceramics and phosphor-in-glass (PiG), have been developed rapidly in recent years on account of their excellent thermal/chemical stability [7][8][9][10]. Among them, PiG, made by co-sintering the up-to-date commercial phosphors and the specially-designed low-melting glass frit, is believed to be the most promising candidate as the color converter considering its outstanding optical performance and simple fabrication process.…”

Nano-Structured Optical Fibers Made of Glass-Ceramics, and Phase Separated and Metallic Particle-Containing Glasses

“…An example of such analysis is shown in Figure 1a-c. Scanning electron microscopy (SEM) is also commonly used to image the surface of the PCGs from nano-to micrometre scale depending on the size of the crystallites and the resolution of the instrument. SEM can also provide information about the composition of the nanophase when combined with energy dispersive X-ray spectroscopy accessory (EDX) [17,[109][110][111][112]. An example of combined a SEM/EDX analysis is shown in Figure 1d.…”