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 ele ctron emission microscopy (BEEM). In the BEEM spectra the miniband man ifests itself as clear peak in the second derivative of the ballistic electron current. Biasing the superlattice results in a shift of the m iniband position and the corresponding peak position. It is shown that the measured total transmission of the superlattice is in excellent a greement with the calculated transmission, which makes the superlattic e a promising tunable energy filter for studying the energetic distrib ution of ballistic electrons. (C) 1998 American Institute of Physics. [S0003-6951(98)03947-3].