Comparison of the quantum efficiencies of interwell and intrawell radiative transitions in quantum cascade lasers
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چکیده
A theoretical study has been made to compare the quantum efficiencies of interwell and intrawell radiative transitions in quantum cascade lasers based on AlxGa1 xAs/GaAs technology. Radiative and non-radiative intersubband transition rates were calculated for a range of temperatures between 4 K and 300 K at an applied electric field of 4 kVcm 1 for structures designed to emit in both mid-infrared and far-infrared frequency ranges. It is found that the internal quantum efficiency of mid-infrared devices is a maximum for diagonal, or interwell, transitions. Conversely, for the far-infrared devices, the quantum efficiency is a maximum for vertical, or intrawell, transitions.
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تاریخ انتشار 1999