Modifying the electronic properties of GaAs∕AlAs superlattices with low-density nitrogen doping

We investigate how low concentrations of N impurities (x<1%) modify the electrical and optical properties of a GaAs∕AlAs superlattice positioned in the intrinsic i region of a p-i-n diode. Increasing x from 0% to 0.9% enhances the integrated intensity of the low temperature electroluminescence emission from the superlattice by more than a factor of 104. We attribute this behavior to reduced transmission of electrons through the superlattice due to the N-induced carrier localization.