Quantum well saturation effect on the reduction of base transit time in light-emitting transistors
Journal
IEEE Transactions on Electron Devices
Journal Volume
61
Journal Issue
10
Pages
3472-3476
Date Issued
2014
Author(s)
Abstract
In this paper, we demonstrate the improvement of cutoff frequency of the light-emitting transistor (LET) due to quantum well (QW) band-filling phenomenon (i.e., saturation) along with the carrier capturing and escaping processes in the base region. Through microwave measurement followed by small-signal model analysis, we observe that the base transit time, τt, of the LET is reduced evidently from 90 to 20 ps when the collector current density increases from 2.43 to 34.9 kA/cm2. The reduction of τtvia saturation effect can be explained by the electroluminescence spectrum and thermionic emission theory of QW.
Type
journal article