BLOCKED IMPURITY BAND DETECTORS

Disclosed is a blocked-impurity-band detector, including an active layer which is doped with a sufficient amount of either a donor or an acceptor impurity that significant charge transport can occur in an impurity band in addition to the charge transport of electrons in the conduction band of the layer and of holes in the valence band of the layer. A blocking layer is disposed on the active layer and contains a sufficiently low concentration of impurities that significant charge transport cannot occur in the blocking layer except by means of electrons in the conduction band of the layer or holes in the valence band of the layer. First and second electrodes are provided for applying a bias potential across the active and blocking layers.