Study of vertical hole transport in InAs/InAsSb type-II superlattices by steady-state and time-resolved photoluminescence spectroscopy

It is known that the vertical hole mobility in superlattice structures, such as InAs/InAs1−xSbx type-II superlattices, is low and limits their photodetector performance. This paper reports the determination of vertical hole mobility in these superlattices with bandgaps in the mid-wave infrared range by using two methods based on steady-state and time-resolved photoluminescence measurements at 12 K–210 K. An ambipolar diffusion model is adopted to extract the hole mobility. The results show that the hole mobility first increases from 0.2 cm2/V s at 12 K and then levels off at ∼50 cm2/V s as the temperature exceeds ∼60 K.