  We present the concept and experimental realization of polarization-induced
bulk electron doping in III-V nitride semiconductors. By exploiting the large
polarization charges in the III-V nitrides, we are able to create wide slabs of
high density mobile electrons without introducing shallow donors. Transport
measurements reveal the superior properties of the polarization doped electron
distributions than comparable shallow donor doped structures. The technique is
readily employed for creating highly conductive layers in many device
structures.
