Density-Matrix Theory of Trionic Spectra in Semiconductor Nanostructures

Abstract

A consistent density-matrix approach for the absorption spectra of semiconductor nanostructures in the presence of a background carrier density is presented. Trionic spectra contain bound and exciton-electron scattering states and exhibit low-energy tails due to energy recoil. The asymmetric trion lineshape is preserved even in the case of weak disorder and optical transitions occur between states of different localization degree.