Two-well terahertz quantum cascade lasers with suppressed carrier leakage
Two-well terahertz quantum cascade lasers with suppressed carrier leakage
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DOI：
10.1063/1.4996567
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发表时间：
2017-09
影响因子：
4
通讯作者：
A. Albo;Y. Flores;Q. Hu;J. Reno
中科院分区：
文献类型：
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作者：
A. Albo;Y. Flores;Q. Hu;J. Reno
限制对角GaAs/ al0.15 - gaas0.85基太赫兹量子级联激光器（thz - qcl）温度性能的机制被确定为电荷载流子通过激发态进入连续体的热激活泄漏。在足够高的势垒支持下，具有高能高层激发态的太赫兹量子激光器旨在消除这些泄漏机制，并改善温度性能。尽管基于谐振声子方案的三阱太赫兹qcl实现了热激活载流子泄漏的抑制，但迄今为止还没有报道温度性能的改善。在这里，我们报告了双量子阱直接声子太赫兹qcl结构的温度性能的重大改进。研究表明，激光性能的提高是由于随着注入势垒高度的增加，热激活载流子泄漏到连续介质中受到抑制。此外，我们还证明了高阻隔双井结构可以支持低密度储层。
The mechanisms that limit the temperature performance of diagonal GaAs/Al0.15GaAs0.85-based terahertz quantum cascade lasers (THz-QCLs) have been identified as thermally activated leakage of charge carriers through excited states into the continuum. THz-QCLs with energetically higher-laying excited states supported by sufficiently high barriers aim to eliminate these leakage mechanisms and lead to improved temperature performance. Although suppression of thermally activated carrier leakage was realized in a three-well THz-QCL based on a resonant-phonon scheme, no improvement in the temperature performance was reported thus far. Here, we report a major improvement in the temperature performance of a two-quantum-well direct-phonon THz-QCL structure. We show that the improved laser performance is due to the suppression of the thermally activated carrier leakage into the continuum with the increase in the injection barrier height. Moreover, we demonstrate that high-barrier two-well structures can support a cl...