Screening of the quantum-confined Stark effect in AlN/GaN nanowire   superlattices by Germanium doping
  We report on electrostatic screening of polarization-induced internal electric fields in AlN/GaN nanowire heterostructures with Germanium-doped GaN nanodiscs embedded between AlN barriers. The incorporation of Germanium at concentrations above $10^{20}\,\text{cm}^{-3}$ shifts the photoluminescence emission energy of GaN nanodiscs to higher energies accompanied by a decrease of the photoluminescence decay time. At the same time, the thickness-dependent shift in emission energy is significantly reduced. In spite of the high donor concentration a degradation of the photoluminescence properties is not observed. 
P. Hille, J. M\"u{\ss}ener, P. Becker, M. de la Mata, N. Rosemann, C.   Mag\'en, J. Arbiol, J. Teubert, S. Chatterjee, J. Sc...
cond-mat.mtrl-sci