Base transport dynamics in a heterojunction bipolar transistor

Abstract
We have used hot‐electron spectroscopy to study nonequilibrium electron transport in the base of a heterojunction bipolar transistor. Electrons injected from an n‐type AlGaAs emitter into a p‐type GaAs base were found to be strongly scattered such that they could be characterized by an effective electron temperature after traversing several hundred angstroms. The effective electron temperature, measured at 4.2 K, was found to be 150 K for a sample having a 900‐Å base region and 500 K for a sample having a 450‐Å base region.