Transport via excitonic complexes in resonant tunneling structures

In this work we study the formation of neutral and negatively charged excitons in double barrier diodes under bias, and how they contribute to transport. We observe a pre-resonance shoulder in the current-voltage curve, which is associated to trion-assisted tunneling of electrons. We analyze this phenomenon by measuring also the quantum-well photoluminescence emission. This trion-assisted mechanism is terminated when trion complexes are dissociated either by thermal excitation or by scattering with free carriers in the quantum well. A simple phenomenological rate equation model allows us confirming the hypothesis of charge transport via a trion state and the proposed methods of termination