Applicability of the High Field Model: A Preliminary Numerical Study

In a companion presentation, we have discussed the theory of a mesoscopic/macroscopic model, which can be viewed as an augmented drift-diusion model. Here, we describe how that model is used. The device we consider for this presentation is the one dimensional GaAs n1, required for the high eld model, is satised only in an interval given approximately by [0.2, 0.5]. When we run both the DD model and the new high eld model in this restricted interval, with boundary conditions of concentration n and potential provided by the HD results, we demonstrate that the new model outperforms the DD model. This indicates that the high eld and DD models should be used only in parts of the device, connected by a transition kinetic regime. This will be a domain decomposition issue involving interface conditions and adequate numerical methods. Keywords: Augmented drift-diusion, high eld model, domain decomposition, ENO algorithm Acknowledgments: The second author is supported by the National Science Foundation under grant DMS-9623037. The third author is supported by the National Science Foundation under grant DMS-9424464. The fourth author is supported by the National Science Foundation under grants ECS-9214488 and ECS-9627849, and the Army Research Oce under grant DAAH04-94-G-0205. Computation is supported by the Pittsburgh Supercomputer Center. Politecnico di Milano, 20133 Milano, Italy.