Photocurrent induced by intersubband transition in a type II and broken-gap quantum well system

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. A sharp peak can be observed in conductance within sub-THz bandwidth. The peak shifts to the lower frequency (red-shift) with increasing temperature. Our results indicate that InAs/GaSb based quantum well systems are of potential to be applied as sub-THz photovoltaic devices