Low Temperature Physics: 33, 137 (2007); https://doi.org/10.1063/1.2409650 (10 pages)
Fizika Nizkikh Temperatur: Volume 33, Number 2-3 (February 2007), p. 194-206 ( to contents , go back )
Vertical transport in a type II broken-gap heterojunction GaInAsSb/p-InAs
V.А. Berezovets1,2, К.D. Мoiseev1, V.I. Nizhankovski2, М.P. Мikhailova1, R.V. Parfeniev1, and Yu.P. Yakovlev1
1A.F. Ioffe Physical-Technical Institute, RAS, 26 Politechnicheskaya Str., St. Petersburg, 194021, Russia
2Международная лаборатория сильных магнитных полей и низких температур Вроцлав, 50-204, Польша
Received August 14, 2006
In a type II broken-gap heterojunction P(N)-GaInAsSb/p-InAs with a sharp planar heteroboundary (a transition layer is about 1.2 nm) the formation of self-consistent quantum wells for electrons and holes is controlled by energy bands overlapping at the heterointerface with varying type and level of the doping of the contacting semiconductors. The study into vertical magnetotransport across the type II broken-gap heterointerface demonstrates that an enhance of 2D-electron localization in the electron channel at the heteroboundary gives rise to a «soft» Coulomb gap in the tunnel density of states. A transition from the state with a «soft» Coulomb gap to the insulator state (a hard energy gap at conductivity stun ~10-8 Ом–1) was observed when the density of states at the Fermi level was negligible as compared with the energy gap between the nearest Landau levels at magnetic field. The threshold yield of the insulator state is due to the delocalisation of electron states at the Landau level nearest to the Fermi level.
PASC: 73.43.–f Quantum Hall effects;
Key words: type II heterojunction, Coulomb gap, seft-consistent quantum wells.