Mid-IR Type-II QW Interband Cascade Lasers: modelling of the device and analysis of the degradation mechanisms

The aim of this work of thesis is to analyze the performance and reliability of the Mid-IR Type II QW interband cascade laser. The analysis has been carried out making use of different simulation software, due to the complex quantum-mechanical processes on the basis of its operation. The laser samples that were object of the study are subdivided into three classes that differed in terms of substrate material namely GaSb, GaAs or silicon, and therefore in terms of defects density within the device. Several accelerated ageing experiments were performed and the results obtained were used to formulate explanation upon the degradation mechanisms that affect this kind of semiconductor MIR laser diodes. Experimental results indicate that the devices exhibit a weak dependence on degradation mechanisms, independently from the material employed for the substrate. This aspect is fundamental because it paves the way towards the development of III-V semiconductor lasers integrated on Si-based based photonic platforms, thus allowing also the implementation by the industry inside mass scale applications, from interconnect to on-chip sensing. Simulations reveal that conduction-limiting processes, associated with carrier injection and extraction from the active region, are linked to subbands misalignment.