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...

中文翻译：

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抑制载流子泄漏的双井太赫兹量子级联激光器

限制对角 GaAs/Al0.15GaAs0.85 基太赫兹量子级联激光器 (THz-QCL) 温度性能的机制已被确定为电荷载流子通过激发态热激活泄漏到连续介质中。具有由足够高的势垒支持的高能激发态的 THz-QCL 旨在消除这些泄漏机制并提高温度性能。尽管在基于谐振声子方案的三井 THz-QCL 中实现了热激活载流子泄漏的抑制，但迄今为止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 THz-QCL 结构的温度性能的重大改进。我们表明，改进的激光性能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的抑制。此外，我们证明了高阻隔的双井结构可以支持...