Abstract
Electron transmission and reflection coefficients are calculated for both (100) and (110) orientated GaAs-AlxGa1-xAs heterojunctions. The excitation amplitudes of evanescent states together with real-space intervalley transfer are presented. Complex band structures at each interface are also calculated. Resonances, characteristic of surface states, are observed at both interfaces. Effective-mass theory, in several of its forms, is discussed in the light of the results.