Type-II band alignment between GaAs and inadvertent interlayers at (In,Ga)P/GaAs interfaces

P. Krispin, A. Knauer
Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin, Germany
Ferdinand-Braun-Institut für Höchstfrequenztechnik, Albert-Einstein-Straße 11, D-12489 Berlin, Germany

Published in:
Applied Physics Letters, 81 (2002) pp. 262-264
© 2002 American Institute of Physics. All rights reserved.


Abstract:
Capacitance-voltage measurements on metal-semiconductor contacts are used to examine vertical depth profiles of the electron concentration in n-type (In,Ga)P/GaAs heterostructures. The electron distributions at single interfaces are compared with calculations based on solutions of the Schrödinger-Poisson equations. It is shown that distinct interlayers may be formed at both the (In,Ga)P-on-GaAs and the GaAs-on-(In,Ga)P interfaces. The inadvertent interlayers are identified by their conduction band offsets. Under certain growth conditions, the band alignment between GaAs and the interlayers is determined in the investigated heterostructures to be of type II.