This paper investigates the impact of dislocation density and active layer structure on the degradation mechanisms of 1.3 $\mu \text{m}$ InAs Quantum Dot (QD) lasers for silicon photonics. We analyzed the optical behavior of two sets of samples, having different dislocation densities and different number of quantum dot layers in the active region. The samples were subjected to a short-term step-stress experiment and to long-term constant current operation in order to investigate the dominant degradation processes. The results indicate that: (i) the temperature stability is much higher in the devices grown on native substrate, thanks to the lower defect density; (ii) the roll-off current is considerably higher for the devices with higher number of layers, due to the lower density of carriers in the QDs; (iii) in nominal ground-state operating regime, the degradation rate is limited by the density of dislocations, that may serve as preferential paths for the diffusion of non-radiative recombination centers; (iv) at extreme injection levels and operating temperatures, the devices exhibit a blue shift of the spectral emission; possible explanations for this process are discussed in the paper.

中文翻译：

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1.3 μm InAs 量子点激光二极管的退化：位错密度和量子点层数的影响

本文研究了位错密度和有源层结构对用于硅光子学的 1.3 $\mu \text{m}$ InAs 量子点 (QD) 激光器退化机制的影响。我们分析了两组样品的光学行为，在有源区具有不同的位错密度和不同数量的量子点层。对样品进行短期阶跃应力实验和长期恒流操作，以研究主要的降解过程。结果表明：（i）由于较低的缺陷密度，在原生衬底上生长的器件的温度稳定性要高得多；(ii) 由于 QD 中载流子密度较低，因此层数较多的器件的滚降电流要高得多；(iii) 在标称基态运行状态下，降解率受到位错密度的限制，位错可能作为非辐射复合中心扩散的优先路径；(iv) 在极端的注入水平和工作温度下，器件表现出光谱发射的蓝移；文件中讨论了对该过程的可能解释。