  In quantum-dot tunnel-injection lasers, the excited charge carriers are
efficiently captured from the bulk states via an injector quantum well and then
transferred into the quantum dots via a tunnel barrier. The alignment of the
electronic levels is crucial for the high efficiency of these processes and
especially for the fast modulation dynamics of these lasers. In particular, the
quantum mechanical nature of the tunneling process must be taken into account
in the transition from two-dimensional quantum well states to zero-dimensional
quantum dot states. This results in hybrid states, from which the scattering
into the quantum-dot ground states takes place. We combine electronic state
calculations of the tunnel-injection structures with many-body calculations of
the scattering processes and insert this into a complete laser simulator. This
allows us to study the influence of the structural design and the resulting
electronic states as well as limitations due to inhomogeneous quantum-dot
distributions. We find that the optimal electronic state alignment deviates
from a simple picture in which the of the quantum-dot ground state energies are
one LO-phonon energy below the injector quantum well ground state.
