Ballistic electron emission microscopy on biased GaAs-AlGaAs superlattices

In this work, ballistic electron transport through the lowest miniband of a biased GaAs-AlGaAs superlattice is investigated by ballistic electron emission microscopy (BEEM). In the BEEM spectra the miniband manifests itself as clear peak in the second derivative of the ballistic electron current. Biasing the superlattice results in a shift of the miniband position and the corresponding peak position. It is shown that the measured total transmission of the superlattice is in excellent agreement with the calculated transmission, which makes the superlattice a promising tunable energy filter for studying the energetic distribution of ballistic electrons. (C) 1998 American Institute of Physics. [S0003-6951(98)03947-3].