Deep UV Laser at 249 nm Based on GaN Quantum Wells
Deep UV Laser at 249 nm Based on GaN Quantum Wells
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基于 GaN 量子阱的 249 nm 深紫外激光器
DOI：
10.1021/acsphotonics.9b00882
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发表时间：
2019-10-01
期刊：
影响因子：
7
通讯作者：
Li, Xiaohang
中科院分区：
文献类型：
--
作者：
Shan, Maocheng;Zhang, Yi;Li, Xiaohang
在这封信中，我们报告的深紫外激光发射在249 nm的薄GaN量子威尔斯（QWs）的基础上，在室温下的光泵浦。激光阈值为190 kW/cm 2，与类似波长下的最先进AlGaN QW激光器相当。该激光器结构通过金属有机化学气相沉积在c平面蓝宝石衬底上赝晶生长，包括40对4个单层（ML）GaN QW夹在6个ML AlN量子势垒（QB）之间。在波长处的低阈值归因于大的光学和量子限制以及材料、界面和法布里-珀罗刻面的高质量。由于GaN的价带特性，阈值以下和阈值以上的发射都由横向电极化主导。这项工作明确地表明了二元AlN/GaN异质结的高性能紫外发射器的潜力。
In this Letter, we report on deep UV laser emitting at 249 nm based on thin GaN quantum wells (QWs) by optical pumping at room temperature. The laser threshold was 190 kW/cm2 that is comparable to state-of-the-art AlGaN QW lasers at similar wavelengths. The laser structure was pseudomorphically grown on a c-plane sapphire substrate by metalorganic chemical vapor deposition, comprising 40 pairs of 4 monolayer (ML) GaN QWs sandwiched by 6 ML AlN quantum barriers (QBs). The low threshold at the wavelength was attributed to large optical and quantum confinement and high quality of the material, interface, and Fabry-Perot facet. The emissions below and above the threshold were both dominated by transverse electric polarizations thanks to the valence band characteristics of GaN. This work unambiguously demonstrates the potentials of the binary AlN/GaN heterojunctions for high-performance UV emitters.