Stationary states and phase diagram for a model of the Gunn effect under realistic boundary conditions

TL;DR

This paper develops a realistic boundary condition framework for the Gunn effect in semiconductors, revealing bistability, hysteresis, and various dynamic regimes influenced by contact parameters.

Contribution

It introduces a physically grounded boundary condition formulation and analyzes its impact on the stationary and dynamic behavior of the Gunn effect model.

Findings

Bistability and hysteresis occur under certain contact conditions.

Multiple Gunn effect regimes are predicted depending on contact parameters.

Contacts play a critical role in the behavior of the Gunn effect.

Abstract

A general formulation of boundary conditions for semiconductor-metal contacts follows from a phenomenological procedure sketched here. The resulting boundary conditions, which incorporate only physically well-defined parameters, are used to study the classical unipolar drift-diffusion model for the Gunn effect. The analysis of its stationary solutions reveals the presence of bistability and hysteresis for a certain range of contact parameters. Several types of Gunn effect are predicted to occur in the model, when no stable stationary solution exists, depending on the value of the parameters of the injecting contact appearing in the boundary condition. In this way, the critical role played by contacts in the Gunn effect is clearly stablished.