Studies on magneto transport of InN and GaN based on two layer model

摘要

InN is a material of huge potential in device applications. InN is grown on sapphire substrate. But due to the large lattice mismatch between the sapphire and InN, the large number of dislocations develops near the interface between the two materials. However, the density of threading dislocation falls sharply in the bulk layer. The charge density has also similar variation. So the bulk InN crystal may be treated to be consisting of two layers, one the interfacial layer where the density of dislocations is very high and the layer on the interfacial layer which is called bulk layer which has much lower density of dislocation and is considered to be negligible. We have calculated the mobility and magneto resistance of InN based on two layer model. We find that the theoretical values of mobility based on two layer model matches quite well with the experimental data. The variation in the theoretical values of magneto resistance is in good agreement with that of experimental values. In our model, the dislocation scattering and ionized impurity scattering mechanisms are considered in the interfacial layer and for the bulk layer, the acoustic phonon scattering via deformation potential and piezo electric coupling, ionized impurity scattering and optical phonon scattering mechanisms are considered. Dislocations affect the values of mobility as also the magneto resistance.