EFFECTIVE MASS IN THE BARRIERS OF GAAS/ALAS RESONANT TUNNELING DOUBLE BARRIER DIODES

We have investigated the peak and valley currents for a series of resonant tunneling diodes with AlAs barriers having widths in the range 1.9-5.9 nm and GaAs wells fabricated on GaAs substrates. Using a simple WKB expression that assumes resonant tunneling dominated by transfer through the Γ-Γ conduction band edge, a value for the strength, mb*Vb, of our AlAs barriers is found to be 0.069 ± 0.01 eV and the effective mass is found to be mb = (0.068 ± 0.01)m0. This agrees to within the measurement error with the result obtained for a series of diodes fabricated on InP by Broekaert et al.1 with In0.53Ga0.47As wells and pseudomorphic AlAs barriers. The measured peak currents are compared with the results of self-consistent numerical solutions of Poisson's and Schroedinger's equations using the deduced effective mass. © 1992.