DOMINANT PHOTOGENERATED VALLEY CURRENT IN A DOUBLE-BARRIER RESONANT-TUNNELING DIODE

Dominant photogenerated valley current has been observed in an optical ly-excited InGaAs/AlAs double-barrier resonant-tunneling diode. The ph otogenerated valley current in the resonant-tunneling diode varies wit h the optical power level. Under intense illumination, the photogenera ted valley current increases to such a high level that it becomes domi nant over the peak current. As a consequence, the negative differentia l resistance of the device is removed. The observed photogenerated val ley current is described by photogenerating electron-hole pairs in the depletion region adjacent to the double-barrier structure. Transient behavior of the photogenerated carriers is also studied. The observed dominant photogenerated valley current may have useful applications. ( C) 1994 American Institute of Physics.