| Popis: |
We have calculated the tunneling of holes in single -barrier and double -barrier GaAs /A1GaAs diodes using a ten -band,empirical tight- binding model. Transfer matrices are used to model the wave -function on a layer -by -layer level allowing for a simple, transparent imposition of an electric field, and the mixing of heavy, light and splitoff valence band states. Transmission resonances have been found, and hole currents calculated at 77 degrees K. Mixing of different hole states hasbeen examined as a function of aluminum fraction and thickness of the barriers and well. Introduction The tunneling of electrons has received a great deal of attention since the advent of fabrication techniques capable ofgrowing extremely thin (10A- 100is) layers of semiconducting materials. Tsu and Esakil provided a basic model for calcu-lating the transmission of carriers in a superlattice comprised of a few barriers and wells. Since that time, there have been many theoretical and experimental investigations into the tunneling of electrons in semiconducting systems. However |
