Investigations of the quantum photovoltaic effect in InAs-GaSb semiconductor superlattices

We report the observation in InAs-GaSb semiconductor superlattices of a photovoltaic effect that has a quantum origin, as it arises from the spatial separation of the electron and hole ground-state wave functions in these type II superlattices. The results are consistent with the simplest theoretical predictions, except for the voltage sign, which evidences a depopulation of the surface layer.