Electro-optical examination of the band structure of ordered InGaAs

• Published in: Applied physics letters Vol. 76; no. 1; pp. 88 - 90
• Main Authors: Spieler, J., Kippenberg, T., Krauß, J., Kiesel, P., Döhler, G. H., Velling, P., Prost, W., Tegude, F. J.
• Format: Journal Article
• Language: English
• Published: 03-01-2000
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.125665

Using electroabsorption measurements, we have studied the effects of atomic superlattice ordering on the electronic band structure of InGaAs for different growth parameters. We have observed ordering-induced polarization anisotropy, valence-band splitting and band gap reduction strongest for 550 °C growth and 2°[111]B tilted substrates. Back-folded conduction-band states show an ordering dependent energy shift. The position of the split-off valence-band, however, is almost unaffected. An extension to extremely low growth temperatures exhibits ordering also for 450 °C growth. Atomic force microscopy measurements reveal a temperature-dependent change of InGaAs surface from step-like to island formation.