The effect of injector barrier thickness and doping level on current transport and optical transition width in a λ ∼ 8.0 μm quantum cascade structure

Scott S. Howard, Daniel P. Howard, Kale Franz, Anthony Hoffman, Deborah L. Sivco, Claire F. Gmachl

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

We experimentally study the optical transition width and current transport properties of a set of λ ∼ 8.0 μm quantum cascade (QC) structures with varying injector barrier thickness and doping level. For this high-performance QC laser structure, a 50% reduction in doping level and a 33% reduction in injection barrier thickness yield five times stronger luminescence, 20% smaller optical transition linewidth, and improved current-voltage characteristics. These results demonstrate how high-performance QC laser structures can be engineered to produce narrow gain spectra at and above room temperature.

Original languageEnglish (US)
Article number191107
JournalApplied Physics Letters
Volume93
Issue number19
DOIs
StatePublished - Nov 21 2008

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

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