PEAK-TO-VALLEY RATIO OF SMALL RESONANT-TUNNELING DIODES WITH VARIOUS BARRIER-THICKNESS ASYMMETRIES

Resonant tunneling through small double-barrier heterostructures is in vestigated in dependence of the charge accumulation in the quantum wel l and the device diameter. The study comprises a series of resonant-tu nneling diodes with four different barrier-thickness ratios and diamet ers between 300 nm and 10 mu m. Special emphasis lies on the peak-to-v alley ratio of the resonant-tunneling current peaks, which drops drast ically with decreasing device diameter for weak electron accumulation, while it is size independent in the strong-charging case. (C) 1996 Am erican Institute of Physics.