Photosensitive Coulomb blockade in semiconductor p‐n tunnel diodes

Data and arguments are presented identifying the old phenomenon (1960) of the ‘‘zero‐bias anomaly’’ in III‐V semiconductor p‐n tunneling as a manifestation of the Coulomb blockade. Tunneling involving a Au‐Ge complex in GaAs, which acts as a photosensitive ‘‘quantum dot’’ controlling the p‐n tunneling, provides the basis for a light‐sensitive Coulomb blockade and serves also as a model, an explanation, for the zero‐bias anomaly (V=0) observed in III‐V p‐n tunneling.