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Full-band simulations of InP/GaAsSb/InP Double Heterojunction Bipolar Transistors (DHBTs)

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Creating Full-band simulations Double Heterojunction Bipolar Transistors.jpg

Short Description

The Laboratory for Millimeter Wave Electronics (MWE) of the ETHZ is developing and fabricating InP/GaAsSb/InP DHBTs for application in modern lightwave communication systems. The conduction band edge of the GaAsSb base sits above the conduction band edge of the InP collector, thus realizing an injection ramp for electrons reaching the base/collector junction and improving the transistor delay. However, recent studies have shown that electrons situated in the L-valley of the GaAsSb layer cannot be efficiently transferred to the L-valley of InP because the latter is situated at higher energies (see illustration on the left). Such electrons are reflected back towards the emitter side. The reason for this behavior is "momentum conservation": without any external interaction, an electron cannot escape the valley it belongs to. The goal of this project is to investigate with a full-band and atomistic simulator what happens if the GaAsSb/InP junction contains atomic roughness. In this case, momentum conservation is broken and L-valley electrons might eventually transfer from the L-valley of GaAsSb to the Gamma-valley of InP.

Status: Available

Looking for 1 Semester/Master student
Contact: Mathieu Luisier


Interest in device modeling


20% Theory
20% Model Implementation
60% Simulations


Mathieu Luisier

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Detailed Task Description


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