Low-field electron transport mechanism in GaAs Gunn diodes and GaAs/GaAs/sub ins/ layers (MBE)

We present the basis of resistance calculations of Gunn diodes in a magnetic field and its dependence on field direction angle to the diode plane. Also the influence on the experimental results of diode electrode shape is considered. The current transport between electrodes and diode subsurface layers is shown to be tunnelling. For comparison the transport properties of thin GaAs/GaAs/sub ins/ layers are presented. The transport in the thin Gunn diodes layers is significantly better. We consider that the cause of such behaviour is the lower compensation ratio in the VPE layers of Gunn diodes material in contrast to MBE epitaxial layers.