Thermal activation of carriers from a metallic impurity band

S. Liu, K. Karrai, F. Dunmore, H. D. Drew, R. Wilson, G. A. Thomas

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

Transport and far-infrared transmission measurements are reported on Si-doped GaAs epitaxial films (n the Mott density n0). The spectra display a 1s→2p resonance and a Drude response that persists to low temperatures. An analysis of the temperature dependence of the spectra gives the activation energy for thermal excitation of carriers from the metallic impurity band to the conduction band. The effective mass of the impurity band mi is obtained from optical sum-rule considerations. mi appears to diverge at the metal-insulator transition. The large mi implies a correlation-induced narrowing of the impurity band. The activation energy Ea and effective mass mi obtained from optical measurements are consistent with the results obtained from transport measurements. The transmission spectra of Si:P and planar Si-doped GaAs/AlxGa1-xAs superlattices are also discussed.

Original languageEnglish (US)
Pages (from-to)11394-11397
Number of pages4
JournalPhysical Review B
Volume48
Issue number15
DOIs
StatePublished - 1993
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Thermal activation of carriers from a metallic impurity band'. Together they form a unique fingerprint.

Cite this