Abstract

Improving the performances of terahertz (THz) quantum cascade lasers (QCLs) in terms of temperature operation or current threshold is a major challenge. Here new physical insights into the role of scattering mechanisms and the transport properties in THz QCLs are gained by developing an accurate implementation of the non-equilibrium Green’s function formalism. Beyond previous analysis, I will discuss the double role of charge impurity scattering on both the transport properties and on the gain properties. I will show that simultaneous linear and nonlinear effects of the transport and gain properties of the THz QCLs can coexist, resolving apparent contradiction observed in experiments [1]. The optimal position of the dopants is discussed.

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