Suppression of Self-sustained Field Domain Oscillation in GaAs/AlAs Superlattice by Hydrostatic Pressure at Room Temperature

The behavior of room temperature self-sustained current oscillations resulting from sequential resonance tunneling in a doped weakly-coupled GaAs/AlAs superlattice (SL) is investigated under hydrostatic pressure. From atmosphere pressure to 6.5 kbar, oscillations exist in the whole plateau of the I-V curve and oscillating characteristics are affected by the pressure. When hydrostatic pressure is higher than 6.5 kbar, the current oscillations are completely suppressed although a current plateau still can be seen in the 1-V curve. The plateau disappears when the pressure is close to 13.5kbar. As the main effect of hydrostatic pressure is to lower the X point valley with respect to Г point valley, the disappearance of oscillation and the plateau shrinkage before Г - X resonance takes place are attributed to the increases of thermoionic emission and nonresonant tunneling components determined by the lowest Г - X barrier height in GaAs/AlAs SL structure.