Phosphor Glass-Coated Sapphire With Moth-Eye Microstructures for Ultraviolet-Excited White Light-Emitting Diodes
| Autor: | Yingxiang Cai, Linlin Xu, Yang Peng, Hao Wang, Haiding Sun, Jiangnan Dai, Changqing Chen, Jia Li, Yun Mou, Renli Liang, Yang Gao |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | IEEE Transactions on Electron Devices. 66:3007-3011 |
| ISSN: | 1557-9646 0018-9383 |
| Popis: | In this paper, we used a moth-eye structured phosphor-in-glass (PiG) to enhance the luminous efficiency (LE) of ultraviolet (UV)-excited white light-emitting diodes (WLEDs). The proposed PiG was prepared by printing and sintering a red/green phosphor film on a moth-eye array-structured (MAS) sapphire plate. Then, this PiG was directly bonded on a UV-LED flip-chip to achieve an ultra-compact and reliable WLED device. The luminescent performances of the WLEDs were adjusted by managing the thickness of PiG film from 20 to $107~\mu \text{m}$ . When the film thickness is $20~\mu \text{m}$ , the LE of the WLED with the MAS PiG is increased by 20.96% compared to the WLED with the flat PiG, and the correlated color temperature (CCT) is 4712 K and the color rendering index (CRI) is 78.7. It is chiefly attributed to a significant reduction of total internal reflection at the PiG and air interface benefit from using MAS. In addition, the light intensity of the MAS PiG from −80° to 80° is higher than that of the reference PiG. For the reference PiG, the electric field amplitude is strong in the air at $\theta _{s} = \textsf {0} {^{\circ }}$ , and then becomes weak at the critical angle of $\theta _{s} = 36 {^{\circ }}$ . Consequently, the MAS PiG plays a promising role in the luminescent converter for high-quality WLEDs and can significantly improve the luminescent performances. |
| Databáze: | OpenAIRE |
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