Current Fluctuations in Single Barrier Vertical GaAs/AlAs/GaAs Tunneling Devices

J. Przybytek and M. Baj Institute of Experimental Physics, Warsaw University, Hoża 69, 00-681 Warsaw, Poland

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Received: 9 06 2007;

We report the experimental results of the low temperature (T = 4.2 K) low-frequency current fluctuations measurements in the single-barrier resonant tunneling GaAs/AlAs/GaAs device with Si δ-doping in the center of the 10 nm thick AlAs barrier. The dimensions of the device were 200 μm by 200 μm. For the biasing voltages 0.1 V <|U| <1 V we observed the Fano factors between F = 0.7 and F = 0.95. We explain it by the existence of the trapping centers/imperfections/resonant levels inside the barrier participating in the transport for this range of voltages. Only for the smallest biasing voltages the Fano factor tends to F = 1, expected for a highly nontransparent barrier.

DOI: 10.12693/APhysPolA.112.221 PACS numbers: 73.50.Td, 73.40.Gk, 73.43.Jn