Effect of Charge Build-up in Barrier Layers on the Γ Resonance in a GaAs/AlAs Double-Barrier Structure

Resonant tunneling transport in a GaAs/AlAs double-barrier structure has been investigated at 77 K under high hydrostatic pressures before the type II transition. It is experimentally demonstrated that a charge build-up in the emitter AlAs layer results in a large band bending, leading to a large shift of the Γ resonance to a higher bias voltage and non-resonant tunneling components through X states in AlAs causes the increase of the valley current, leading to a smaller peak-to-valley ratio. At high-pressures, the resonant tunneling current peak was observed to decrease significantly.