Influence of carrier diffusion on an anode trapped domain formation in a transferred electron device

This paper presents an influence of the electric field dependence of the diffusion coefficient of electrons (D(E) relation) on a formation of a stable domain at an anode contact in a transferred electron device. The stable domain (anode trapped domain) has been observed in a planar Gunn device experimentally, and it has been shown that a large trigger voltage is needed to launch a new domain if a preceding domain has been trapped. Computer simulations have been carried out in order to find a condition to form the trapped domain. Various D(E) relations of GaAs presented by many authors have been adopted to the simulation, and it is shown that one of these D(E) relations is suitable to describe the dynamic behaviors of electrons in GaAs. Simulated results have indicated that the trapped domain occurs in a certain range of doping density.