Sub-terahertz photoconduction induced by interlayer transition in an InAs/GaSb-based type II and broken-gap quantum well system

In this paper, we demonstrate theoretically that, when an InAs/GaSb-based type II and broken-gap quantum well is subjected to a light field, conductance can be observed along the growth direction due to charge transfer between electron and hole layers which are spatially separated. A peak profile can be observed in the conductance within sub-terahertz bandwidth. The peak shifts to the lower frequency (red-shift) with increasing temperature and a more broadened peak structure can be observed at lower temperatures. Our results suggest that InAs/GaSb-based quantum well systems are of potential to be applied as sub-terahertz photovoltaic devices working at relatively low temperatures.