Ultrahigh Degree of Optical Polarization above 80% in AlGaN-Based Deep-Ultraviolet LED with Moth-Eye Microstructure
Ultrahigh Degree of Optical Polarization above 80% in AlGaN-Based Deep-Ultraviolet LED with Moth-Eye Microstructure
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超高%20度%20of%20光学%20偏光%20以上%2080%%20in%20AlGaN基%20深紫外%20LED%20with%20蛾眼%20微结构
DOI：
10.1021/acsphotonics.8b00899
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发表时间：
2018-08
期刊：
影响因子：
7
通讯作者：
Chen Changqing
中科院分区：
文献类型：
--
作者：
Wang Shuai;Dai Jiangnan;Hu Jiahui;Zhang Shuang;Xu Linlin;Long Hanling;Chen Jingwen;Wan Qixin;Kuo Hao-chung;Chen Changqing
首次在AlGaN基深紫外发光二极管（DUV-LED）中实现了286 nm波长下81.8%的偏振度（DOP）。通过引入在蓝宝石衬底背面制作的新型蛾眼微结构，获得了非常高的DOP。与DOP为64.7%的常规DUV-LED相比，获得了显著的1.26倍增强。值得一提的是，利用自建的全空间横电（TE）、横磁（TM）模光强测试系统，主要由角分辨支架、Glan-Taylor棱镜和光谱仪组成，实现了DOP的精确测量。对于TE和TM模式光，半导体内部的提取角从传统的（−26°，26°）、（−52°，−41°）、（41°，52°）扩展到（−52°，52°）。结合时域有限差分模拟，进一步证实了新型蛾眼微结构能显著削弱全内反射，并能有效地提高反射率。
For the first time, an ultrahigh degree of optical polarization (DOP) of 81.8% in AlGaN-based deep ultraviolet LED (DUV-LED) operated at 286 nm has been experimentally demonstrated. The very high DOP was obtained by introducing the novel moth-eye microstructure fabricated on the backside of a sapphire substrate. Compared with conventional DUV-LED with a DOP of 64.7%, a significant 1.26-fold enhancement was obtained. It was worth mentioning that the DOP was accurately measured via self-built full spatial transverse electric (TE) and transverse magnetic (TM) mode light intensity test system, which was mainly composed of angle resolution bracket, Glan-Taylor prism, and spectrometer. For both TE and TM mode light, the extraction angle inside the semiconductor was extended from conventional (−26°, 26°), (−52°, −41°), (41°, 52°) to (−52°, 52°). Combined with finite difference time domain simulation, it was further confirmed that the novel moth-eye microstructure could notably weaken the total internal reflectio...