Photoconductivity in AlSb/InAs quantum wells

Measuring photoconductivity at low temperatures, the authors investigate the recently observed bipolar behaviour of the persistent photoeffect in InAs/AlSb quantum wells. Depending upon the incident wavelength they observe either a persistent increase or a persistent decrease of the carrier density in the well. They discuss their experimental findings in terms of a simple model based on the band structure as known to date and the growth parameters of the heterostructure.