Electron mobility of inverted InAs/GaSb quantum well structure

We report on the electron mobility of an inverted and a non-inverted type II InAs/GaSb quantum well (QW) structures. It is found that the inverted QW, which has much thicker well width than the non-inverted one, has a smaller electron mobility than the non-inverted one for a wide range of temperature. The result disagrees with the established understanding that the electron mobility increases with increasing the QW width at very low temperature. The smaller mobility is caused by larger electron effective mass since the bottom of the conduction band of the inverted QW becomes a hole-like band due to the mixing between the conduction band and the valence band.