Influence of exciton energy on intersubband transition of chirped superlattice GaAs/AlGaAs quantum cascade laser

摘要

The influence of exciton energy on intersubband transition was simulated for a chirped supperlattice quantum cascade laser of GaAs/AlxGa1-xAs. Exciton energy was modelled as a function of QW width for alloys of various percentages of constituent elements. The results showed that the exciton energy decreased proportionally with increasing QW width. Models were also generated to study exciton energy as a function of the percent alloy contents of AlxGa1-xAs barriers for QWs of various widths. Exciton energy showed characteristics of higher discrete energy when QW width was narrower. Transition energy was also simulated from e(1) and e(2) to the 1s exciton state as functions of applied electric field at various QW widths. Our simulation results showed that the transition energy from e(2) to the 1s exciton state increased proportionally to the increasing strength of the electric field. This transition energy was indicative of THz range radiation.