The operation of quantum dot lasers epitaxially grown on silicon is investigated through a quantum-corrected Poisson-drift-diffusion model. This in-house developed simulation framework completes the traditional rate equation approach, which models the intersubband transitions involved into simultaneous ground-state and excited-state lasing, with a physics-based description of carrier transport and electrostatic effects. The code is applied to look into some of the most relevant mechanisms affecting the lasing operation. We analyze the impact of threading dislocations on non-radiative recombination and laser threshold current. We demonstrate that asymmetric carrier transport in the barrier explains the ground-state power quenching above the excited-state lasing threshold. Finally, we study p-type modulation doping and its benefits/contraindications. The observation of an optimum doping level, minimizing the ground-state lasing threshold current, stems from the reduction of the electron density, which counteracts the benefits from the expected increase of the hole density. This reduction is due to electrostatic effects hindering electron injection.

中文翻译：

---

载流子传输对硅上 QD 激光器连续波性能的影响：漂移扩散方法

通过量子校正泊松漂移扩散模型研究了在硅上外延生长的量子点激光器的操作。这种内部开发的仿真框架完善了传统的速率方程方法，该方法对涉及到同步基态和激发态激光的子带间跃迁进行建模，并对载流子传输和静电效应进行了基于物理学的描述。该代码用于研究影响激光操作的一些最相关的机制。我们分析了穿透位错对非辐射复合和激光阈值电流的影响。我们证明势垒中的不对称载流子传输解释了激发态激光阈值以上的基态功率猝灭。最后，我们研究了 p 型调制掺杂及其好处/禁忌症。观察到最佳掺杂水平，最小化基态激光阈值电流，源于电子密度的降低，这抵消了预期增加的空穴密度带来的好处。这种减少是由于静电效应阻碍了电子注入。