Low temperature transport property of the InSb and InAsSb quantum wells with Al0.1In0.9Sb barrier layers grown by MBE

We investigated difference in the transport properties between Al0.1In0.9Sb/InSb and Al0.1In0.9Sb/InAs0.1Sb0.9 quantum wells (QWs). The resistivity of InSb QWs increases exponentially with decreasing temperature, while that of InAs0.1Sb0.9 QWs is much lower than that of InSb QWs, showing low resistivity even at low temperature. Energy band diagram calculations of InAsxSb1−x/Al0.1In0.9Sb quantum wells (QWs) revealed that the bottom of the conduction band of the InAsxSb1−x well moves downward with increasing As content x. The bottom of the InSb QWs lies above the Fermi level (EF), resulting in depletion of the QW, while that in InAs0.1Sb0.9 QWs lies under EF at low temperature. These calculation results support the experimental difference of the resistivity and sheet carrier density between two types of the QWs well.