Electro-optical examination of the band structure of ordered InGaAs
In: Applied physics letters, Jg. Vol. 76 (2000) ; Heft 1, S. 88 - 90
Zeitschriftenaufsatz / Fach: Elektrotechnik
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 degrees C growth and 2 degrees(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 degrees C growth. Atomic force microscopy measurements reveal a temperature-dependent change of InGaAs surface from step-like to island formation.