Gunn Effect in ZnSe

We have observed the Gunn effect in n-type ZnSe crystals subjected to pulsed electric fields. At room temperature the threshold field is about 38 kV/cm, in rough agreement with the dielectric breakdown field as calculated from Stratton's formulas. In samples showing a spiking mode of current instability, the field outside the domain E1≈22 kV/cm, the domain field E2≥100 kV/cm, the domain drift velocity vdd≈1.0×107 cm/sec, and the peak-to-valley current ratio is about 3:2. Thus, the high-field behavior of ZnSe is similar to that of GaAs, except for the higher characteristic fields. However, current runaway limits operation of ZnSe units to very short pulses and fields near threshold.