Breakup of the conduction band structure of dilute GaAs1-yNy alloys -: art. no. 195307

Using a combination of optical, electrical, and magnetotunneling measurements on resonant tunneling diodes incorporating a GaAs1-yNy. quantum well, we demonstrate that the conduction band states of the GaAs1-yNy layer undergo a marked change with increasing N content. The abrupt change in the electronic properties of GaAs1-yNy. differs significantly from the smoother variation with alloy composition observed in other alloy material systems, such as InxGa1-yAs. We show that the incorporation of N in GaAs gives rise to a qualitatively different type of alloy phenomena: N impurities and N clusters act to localize the extended Bloch states of GaAs at characteristic resonant energies, thus breaking up the energy-wave-vector dispersion relations and reducing the Gamma character of the electronic states near the conduction band edge.