MOVPE-grown AlGaN-based tunnel heterojunctions enabling fully transparent UVC LEDs
MOVPE-grown AlGaN-based tunnel heterojunctions enabling fully transparent UVC LEDs
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DOI：
10.1364/prj.7.0000b7
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发表时间：
2019-05-01
影响因子：
7.6
通讯作者：
Kneissl, Michael
中科院分区：
文献类型：
--
作者：
Kuhn, Christian;Sulmoni, Luca;Kneissl, Michael
我们报告的AlGaN为基础的隧道异质结生长的金属有机气相外延，使完全透明的UVC LED通过消除吸收p-AlGaN和p-GaN层。此外，可以通过利用n-AlGaN层的较高导电性以及n接触的较低电阻来改善电特性。具有AlGaN的UVC LED：Mg/AlGaN：Si隧道结在268 nm处具有单峰发射，证明了有效的载流子注入到AlGaN多量子阱有源区。低带隙中间层的并入使得能够实现有效的隧穿和强电压降低。因此，夹层厚度系统地变化。具有8 nm厚GaN夹层的隧道异质结LED在热翻转附近表现出> 3 mW的连续波发射功率。外量子效率为1.4%，在5 mA的直流电流和20 V的工作电压的晶圆上测量。横向均匀发射的紫外敏感的电致发光显微镜图像证明。完整的UVC LED异质结构在包括镁受体的原位活化的单个外延工艺中生长。(c)2019中国激光出版社
We report on AlGaN-based tunnel heterojunctions grown by metalorganic vapor phase epitaxy enabling fully transparent UVC LEDs by eliminating the absorbing p-AlGaN and p-GaN layers. Furthermore, the electrical characteristics can be improved by exploiting the higher conductivity of n-AlGaN layers as well as a lower resistance of n-contacts. UVC LEDs with AlGaN: Mg/AlGaN: Si tunnel junctions exhibiting single peak emission at 268 nm have been realized, demonstrating effective carrier injection into the AlGaN multiple quantum well active region. The incorporation of a low band gap interlayer enables effective tunneling and strong voltage reduction. Therefore, the interlayer thickness is systematically varied. Tunnel heterojunction LEDs with an 8 nm thick GaN interlayer exhibit continuous-wave emission powers > 3 mWnear thermal rollover. External quantum efficiencies of 1.4% at a DC current of 5 mA and operating voltages of 20 V are measured on-wafer. Laterally homogeneous emission is demonstrated by UV-sensitive electroluminescence microscopy images. The complete UVC LED heterostructure is grown in a single epitaxy process including in situ activation of the magnesium acceptors. (c) 2019 Chinese Laser Press