CAN BARRIERS WITH INVERTED TUNNELING RATES LEAD TO SUBBAND POPULATION-INVERSION

When the conduction-band edge of the quantum wells in a superlattice is close to the valence-band edge of the barriers, the tunneling probabilities out of the quantum well states can be inverted. We examine if this feature can be exploited to achieve intersubband population inversion. If correct matching of the wave function at the interfaces is included, we find that the inversion of the tunneling rates does not persist for low-energy electrons, relevant for intersubband emission.