Highly Luminescent and Photostable Quantum Dot鈥揝ilica Monolith and Its Application to Light-Emitting Diodes
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- 作者：Shinae Jun ; Junho Lee ; Eunjoo Jang
- 刊名：ACS Nano
- 出版年：2013
- 出版时间：February 26, 2013
- 年：2013
- 卷：7
- 期：2
- 页码：1472-1477
- 全文大小：352K
- 年卷期：v.7,no.2(February 26, 2013)
- ISSN：1936-086X
文摘
A highly luminescent and photostable quantum dot鈥搒ilica monolith (QD鈥揝M) substance was prepared by preliminary surface exchange of the QDs and base-catalyzed sol鈥揼el condensation of silica. The SM was heavily doped with 6-mercaptohexanol exchanged QDs up to 12 vol % (26 wt %) without particle aggregation. Propylamine catalyst was important in maintaining the original luminescence of the QDs in the SM during sol鈥揼el condensation. The silica layer was a good barrier against oxygen and moisture, so that the QD鈥揝M maintained its initial luminescence after high-power UV radiation (1 W) for 200 h and through the 150 掳C LED encapsulant curing process. Green and red light-emitting QD鈥揝Ms were applied as color-converting layers on blue LEDs, and the external quantum efficiency reached up to 89% for the green QD鈥揝M and 63% for the red one. A white LED made with a mixture of green and red QDs in the SM, in which the color coordinate was adjusted at (0.23, 0.21) in CIE1931 color space for a backlight application, showed an efficacy of 47 lm/W, the highest value yet reported.