(a) Approximation of the actual screening space-charge distribution occurring within n-type GaN (red curve) with a step function (blue curve), as was originally performed in the model of Read. 35 (b) Approximation of the exact screening space-charge distribution occurring within n-type InN (red curve) with an exponential function fit (blue curve), as has been performed in the present analysis. In Figures 1(a) and 1(b) , , and T denote the average charge, in units of the fundamental electron charge, per dislocation defect site, the bulk donor concentration, and the temperature, respectively. The actual screening space-charge distribution corresponding to n-type GaN was determined using the procedure outlined by Baghani and O’Leary. 43
The four possible occupation states associated with the N-N anti-bonding defect site within the wurtzite 5/7 atom dislocation core structure. The number below each state refers to the net charge of the state in units of the fundamental electron charge.
A schematic diagram for the energy band bending around a dislocation line within n-type InN.
The fraction of N-N anti-bonding energy levels in their possible neutral and charged states, i.e., , and , as a function of the bulk doping concentration for the case of n-type wurtzite InN. The calculations are all performed at 300 K.
The free electron concentration achievable at four different dislocation line densities within n-type wurtzite InN as a function of the bulk doping concentration. The calculations are all performed at 300 K.
Electron Hall mobility limited by scattering from charged dislocation lines within n-type InN. The dashed curve in this figure is after Gallinat et al. 24 and represents a best fit curve to their experimental data.
The material parameters corresponding to wurtzite InN that we employ for the purposes of our calculations. The symbols, , and a, represent the conduction band minimum energy level, the single occupancy N-N anti-bonding energy level, the double occupancy N-N anti-bonding energy level, the relative dielectric constant, the c-lattice constant, and the a-lattice constant, respectively. me denotes the free electron mass. All energies are measured with respect to the valence band maximum energy level.
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