Magneto-transport measurements, carried out at magnetic fields of up to 11T and at between 1.8 and 300K, were used to investigate the scattering mechanisms in GaN/InN/AlN double heterojunctions. Theoretical modelling was based upon a variational approach to solving Boltzmann transport equation. It was found that dislocation scattering was the dominant scattering mechanisms at low temperatures because of the large lattice mismatch with the substrate and hence the high density of dislocations in these material systems. Nevertheless, InN epilayers were characterized by a high background carrier density, probably associated with unwanted impurities. Therefore, also included in the calculations was ionized impurity scattering. However, the effect of ionized impurity scattering as well as the acoustic phonon scattering, remote- background-ionized impurity scattering, and interface roughness scattering on electron mobility were much smaller than that of dislocation scattering. The dislocation densities, in samples with InN thicknesses of 0.4, 0.6 and 0.8 µm, were then determined from the best fit to the experimental data for the low-temperature transport mobility.

Determination of Dislocation Densities in InN. S.Ardali, E.Tiras, M.Gunes, N.Balkan, A.O.Ajagunna, E.Iliopoulos, A.Georgakilas: Physica Status Solidi C, 2012, 9[3-4], 997–1000