Abstract
The role of band discontinuities on electron ionization rates is examined for the case of GaAs/AlGaAs superlattice avalanche photodiode structures. Our results show that the energy discontinuity experienced by a hot electron (E>0.4 eV above the Fermi level) is small or even negative relative to the conduction-band energy discontinuity experienced by an electron at the band edge of the Γ valley in GaAs/AlGaAs heterostructures. This finding does not support the measurement of an enhanced electron ionization rate due to transport through a superlattice composed of this materials system.