|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Engineering / Faculty of Engineering >
Peer-reviewed Journal Articles, etc >
Combustion synthesis of Ca-alpha-SiAlON:Eu2+ phosphors with different Ca concentrations and diluent ratios
This item is licensed under:Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
| Title: | Combustion synthesis of Ca-alpha-SiAlON:Eu2+ phosphors with different Ca concentrations and diluent ratios |
| Authors: | Saito, Genki Browse this author →KAKEN DB | | Kunisada, Yuji Browse this author →KAKEN DB | | Sakaguchi, Norihito Browse this author →KAKEN DB | | Nomura, Takahiro Browse this author →KAKEN DB | | Akiyama, Tomohiro Browse this author →KAKEN DB |
| Keywords: | Phosphor | | Oxynitride | | SiAlON | | Combustion synthesis |
| Issue Date: | 15-Oct-2017 |
| Publisher: | Elsevier |
| Journal Title: | Ceramics international |
| Volume: | 43 |
| Issue: | 15 |
| Start Page: | 12396 |
| End Page: | 12401 |
| Publisher DOI: | 10.1016/j.ceramint.2017.06.106 |
| Abstract: | Yellow Ca-alpha-SiAlON:Eu2+ phosphors for white light-emitting diodes (LEDs) were synthesized by a facile combustion synthesis method using CaO, Eu2O3, alpha-Si3N4, Si, and Al as raw materials. Ca concentrations and diluent ratios were optimized to improve their luminescence properties. The lattice constant and luminescence properties improved as x increased from 0.4 to 1.2 in Ca(x)Si(12-(m+n))Al(m+n)OnN(16-n):En(0.06). The optimum value was x = 1.2. Scanning transmission electron microscopy combined with energy dispersive X-ray analysis detected segregation of Ca and Eu at grain boundaries, which decreased luminescence behavior in the x = 1.4 sample. The influence of Si and Si3N4 diluents was investigated by varying the diluent ratio phi = (CaO + Eu2O3 + alpha-Si3N4)/(CaO + Eu2O3 + a-Si3N4 + Al + Si). Changes in temperature and flame propagation speed were measured during combustion synthesis using two thermocouples. When phi, was less than 0.5, the combustion temperature exceeded 1600 degrees C and the synthesized material contained an amount of the high-temperature beta-SiAlON phase. At phi > 0.7, the reaction temperature fell below 1200 degrees C, and unreacted raw materials remained. The optimum value of phi was 0.6. The internal quantum efficiency of the product synthesized at x = 1.2 and (I, = 0.6 was approximately 35% under 450-nm excitation. According to electron probe X-ray microanalysis, composition varied within individual synthesized particles, which may explain the decrease in emission behavior relative to a commercial product. |
| Rights: | © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ | | http://creativecommons.org/licenses/by-nc-nd/4.0/ |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/75760 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 齊藤 元貴
|
