Operating at high temperatures in the range of thermoelectric coolers is essential for terahertz quantum cascade lasers to real applications. The use of scattering-assisted injection scheme enables an increase in operating temperature. This concept, however, has not been implemented in a short-period structure consisting of two quantum wells. In this work, based on non-equilibrium Green’s function calculations, it emphasizes on the current leakage and parasitic absorption via high-energy states as fundamental limitations in this scheme with short-period. A new design concept employing asymmetric wells composition is proposed to suppress these limitations. A peak gain of 40 cm−1 at 230 K is predicted in the GaAs/AlGaAs semiconductor material system with an emission frequency of 3.5 THz.
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机译：对于实际应用中的太赫兹量子级联激光器，在热电冷却器范围内的高温下运行至关重要。散射辅助注射方案的使用可以提高工作温度。但是，该概念尚未在由两个量子阱组成的短周期结构中实现。在这项工作中，基于非平衡格林函数的计算，它强调了通过高能态的电流泄漏和寄生吸收是该方案短期内的基本限制。提出了一种采用非对称井组成的新设计理念来抑制这些局限性。在GaAs / AlGaAs半导体材料系统中，发射频率为3.5 THz时，在230 K处的峰值增益为40 cm -1 。
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