Recent Developments in Narrow Gap Semiconductor InSb and InAsSb Quantum Wells

Abstract

  Narrow-gap III-V compound semiconductors such as InSb and InAs are indispensable materials for highly sensitive magnetic sensors. We have systematically studied transport properties of Al_0.1In_0.9Sb/InSb and Al_0.1In_0.9Sb/InAs_0.1Sb_0.9 quantum wells: the well-width dependence of sheet resistivity, carrier density and mobility. The carrier density and mobility of InAsSb QWs are higher than those of InSb QWs. The InAs_0.1Sb_0.9 QWs, which lattice mismatch between the well and barrier layers is 0%, shows high mobility regardless of the well width. The calculated band-alignment of these QWs revealed that the bottom of the conduction band of InSb QWs is above the Fermi level, while that of InAs_0.1Sb_0.9 QWs is under the Fermi level, which leads the differece of the carrier density. We also discussed the doping effect into InSb QWs. The doping improves temperature dependence of the mobility and resistivity.