ASYMMETRIC DARK CURRENT IN QUANTUM WELL INFRARED PHOTODETECTORS

Asymmetric dark current versus voltage characteristics in quantum well infrared photodetectors have been studied. A model based on asymmetrical potential barriers was proposed. The asymmetrical potential barriers, which are most likely due to the accumulation of oxygen impurities at one of the interfaces, cause the asymmetrical I‐V characteristics. The height of the potential spike is found to increase with the Al content in the AlGaAs barriers. Calculations based on our model agree well with experimental results.