The dark current caused by the field-induced mixing effect on bound-to-continuum quantum-well infrared photodetectors

Different from the single-barrier Wentzel-Kramer-Brillouin tunnelling and t hermionic emission models, the dark current of bound-to-continuum quantum-w ell infrared photodetectors is theoretically studied by the new approach of the held-induced mixing effect (FIME). Based on the rate balance condition between the loss rate of bound electrons caused by FIME and the net quantu m capture of continuum electrons, the Fermi levels of continuum and bound e lectrons are separated with each other at non-zero bias. In addition to sho wing good agreement with the experimental results without parameter fitting techniques, the variations of dark current with both operating temperature and, voltage bias can also be explained by the Fermi level of continuum el ectrons. With a current suppression ratio to reveal the variations of dark current with structural parameters, the ratio and the temperature region wh ere the dark current is effectively suppressed are both diminished as the b ias increases.