INVESTIGATION OF THE INFLUENCE OF THE WELL AND THE BARRIER THICKNESSES IN GASB/ALSB/GASB/ALSB/INAS DOUBLE-BARRIER INTERBAND TUNNELING STRUCTURES

The tunneling currents of GaSb/AISb/GaSb/AISb/InAs double-barrier interband tunneling (DBIT) structures were studied experimentally by varying the thicknesses of the well and the barrier layers systematically. The optimal thicknesses for the GaSb well and the AlSb barriers were found to be 6.5 and 1.0 nm to obtain a high peak current density (19 kA/cm2), with a large peak-to-valley ratio (PVR) of 4. The high peak current in the DBIT structure shows the strong effect of the resonant coherence of the wave function across the double barrier. For the case of a small GaSb well width (3 nm), a drastic reduction of the peak current was observed, an effect suggesting that the electron wave function in the InAs couples primarily to the quantized light hole state in the GaSb well. © 1990 IEEE