Strain dependence of the valence-band offset in InAs/GaAs heterojunctions determined by ultraviolet photoelectron spectroscopy
| Autor: | A. Förster, R. Kohleick, Hans Lüth, C. Ohler |
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| Rok vydání: | 1994 |
| Předmět: | |
| Zdroj: | Physical Review B. 50:7833-7837 |
| ISSN: | 1095-3795 0163-1829 |
| DOI: | 10.1103/physrevb.50.7833 |
| Popis: | We have used ultraviolet photoelectron spectroscopy to study the strain dependence of the valence-band offset in situ for InAs/GaAs(100) heterojunctions grown by molecular-beam epitaxy. The Ga 3${\mathit{d}}_{5/2}$ and In 4${\mathit{d}}_{5/2}$ core-level to valence-band-maximum binding-energy separations and the Ga 3${\mathit{d}}_{5/2}$ to In 4${\mathit{d}}_{5/2}$ core-level energy separations were measured as functions of strain. This requires the growth of fully relaxed ${\mathrm{In}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As buffer layers of varying composition as virtual substrates. We account for the true shape of the density of states near the valence-band edge by using results of k\ensuremath{\cdot}p theory. Thus a full empirical pseudopotential calculation can be avoided. Our measurements yield valence-band offset values of 0.04\ifmmode\pm\else\textpm\fi{}0.10 eV for InAs strained to GaAs(100), 0.57\ifmmode\pm\else\textpm\fi{}0.10 eV for GaAs strained to InAs, and 0.36\ifmmode\pm\else\textpm\fi{}0.06 eV for both strained to InP(100), respectively, the valence-band maximum being lower at the InAs side of the junction. |
| Databáze: | OpenAIRE |
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