Electron-drift-mobility measurements and exponential conduction-band tails in hydrogenated amorphous silicon-germanium alloys

Qi Wang, Homer Antoniadis, Eric Allan Schiff, S. Guha

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

We have measured the temperature dependence of the electron drift mobility using the time-of-flight technique for a series of undoped hydrogenated amorphous silicon-germanium alloys with band gaps spanning the range 1.471.72 eV. We also developed techniques for analyzing dispersion effects in such measurements, which permitted us to compare essentially all previous measurements with our own. We draw two main conclusions. First, there is substantial agreement between laboratories for the reduction in the electron drift mobility due to Ge alloying. Second, we are able to account for most of the features of the data using the standard multiple-trapping model by invoking only variations of an exponential conduction-band-tail width scrEC0; we find a fair linear correlation between this width and the optical band gap scrET. The effects of alloying upon the microscopic mobility and the attempt-to-escape frequency were relatively minor.

Original languageEnglish (US)
Pages (from-to)9435-9448
Number of pages14
JournalPhysical Review B
Volume47
Issue number15
DOIs
StatePublished - 1993

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germanium alloys
silicon alloys
Amorphous alloys
Conduction bands
Amorphous silicon
Alloying
amorphous silicon
conduction bands
alloying
Electrons
Optical band gaps
Energy gap
electrons
escape
trapping
temperature dependence
Temperature
Si-Ge alloys

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Electron-drift-mobility measurements and exponential conduction-band tails in hydrogenated amorphous silicon-germanium alloys. / Wang, Qi; Antoniadis, Homer; Schiff, Eric Allan; Guha, S.

In: Physical Review B, Vol. 47, No. 15, 1993, p. 9435-9448.

Research output: Contribution to journalArticle

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