Exciton Dynamics and Charge Carrier Transport in SiGeSn Based MQW Devices

SiGeSn alloys have emerged as a versatile material system for integrated photonics, combining tunable bandgap engineering with strong light-matter interaction across the nearto mid-infrared spectrum. In this work, we investigate the dynamics of excitons and charge carriers in SiGeSn quantumconfined heterostructures using a tight-binding framework. The coupled equations of motion for electrons, holes, and excitons are solved in Liouville superoperator form, enabling a modular incorporation of optical excitation, relaxation, and boundary conditions via density-matrix approach. The interplay between electronic and optical responses is explicitly modeled, with a coherent light-field source term driving the system out of equilibrium, including polarization dynamics and absorption. Our method has been applied to study non-equilibrium exciton dynamics in SiGeSn nanostructures and complements recent experimental work on MQW devices by reproducing key trends in the device performance, thereby offering a predictive and scalable framework for the design of integrated mid-infrared photonic components.