Resonant tunneling through single GaAlAs barriers

Abstract

The current-voltage characteristics of molecular beam epitaxy grown GaAlAs barriers, imbedded in ni type doped GaAs, have been recorded in the range 77 to 300 K and analyzed. Below ~1 3 0 K and for high enough electric fields, oscillations appear on these characteristics that can be quantitatively accounted for by the phenomenon of resonant tunneling. The fit between theory and experiment allows tjo deduce the band discontinuity (250 meV), equal to the expected value for electron tunneling into the r band. Defects have then been introduced by irradiation to evaluate the concentration of scattering centers necessary to destroy these oscillations. The band offset becomes 380 meV when defectas are present which indicates that defect scattering induces tunneling into the X band.