Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Engineering
Consequences Of Valley Filtering On Abrupt Junction Algaas/Gaas Heterojunction Bipolar Transistors, Amitava Das, Mark S. Lundstrom
Consequences Of Valley Filtering On Abrupt Junction Algaas/Gaas Heterojunction Bipolar Transistors, Amitava Das, Mark S. Lundstrom
Department of Electrical and Computer Engineering Faculty Publications
Electron transport in AlGaAs/GaAs heterojunction bipolar transistors with compositionally abrupt emitter‐base junctions is examined. Transport across the abrupt emitter‐base heterojunction is treated quantum mechanically, and the Monte Carlo technique is used to study transport through the base. Although there is a sizeable population of upper‐valley electrons in the bulk emitter, the AlGaAs/GaAs heterojunction is found to favor the injection of Γ‐valley electrons into the base. This valley filtering effect enhances device performance by reducing base transit time, but quantum mechanical tunneling lowers the average energy of the injected flux which increases base transit time. The design of a heterojunction bipolar …
Effective Minority‐Carrier Hole Confinement Of Si‐Doped, N+‐N Gaas Homojunction Barriers, H. L. Chuang, M. E. Klausmeier-Brown, Michael R. Melloch, Mark S. Lundstrom
Effective Minority‐Carrier Hole Confinement Of Si‐Doped, N+‐N Gaas Homojunction Barriers, H. L. Chuang, M. E. Klausmeier-Brown, Michael R. Melloch, Mark S. Lundstrom
Department of Electrical and Computer Engineering Faculty Publications
he electrical performance of Si‐doped n+‐n GaAs homojunction barriers grown by molecular‐beam epitaxy (MBE) is characterized and analyzed. We employed a successive etch technique to study hole injection currents in GaAs n+‐n‐p+ solar cells. The results of the analysis show that minority‐carrier holes in our MBE‐grown material have a mobility of 293 cm2/V s for an n‐type Si‐doping level of 1.5×1016 cm−3 at 300 K. The interface recombination velocity for these homojunction barriers is estimated to be less than 1×103 cm/s, and it appears to be comparable to that recently observed for …