VOLTAGE SWITCHING AND OSCILLATIONS IN A SINGLE BARRIER HETEROSTRUCTURE HOT-ELECTRON DIODE

S-type negative differential conductivity and relaxation oscillations in a single-barrier n(-)-GaAs/Al0.34Ga0.66As/n(+)-GaAs heterostructure hot-electron diode are studied experimentally and by ensemble Monte C arlo simulations at 300 and 77 K lattice temperature. The influence of interband impact ionization on the instability is investigated. The f requency is found to be limited by a slow electron dispersal from the accumulation layer adjacent to the n(-)-GaAs/Al0.34Ga0.66As interface to less than 10 GHz. The maximum frequency of the oscillations observe d experimentally was about 0.5 GHz on account of the parasitic capacit ance of the investigated device structure. (C) 1998 American Institute of Physics. [S0021-8979(98)01019-6].