ELECTRON MULTIPLICATION IN ALXGA1-XAS GAAS HETEROSTRUCTURES/

We have measured the electron multiplication characteristics of thin ( similar to 0.1 mu m) AlxGa1-xAs(500 Angstrom)/GaAs(500 Angstrom) singl e heterostructures with 0.3 less than or equal to x less than or equal to 0.6, grown in a p-i-n configuration. In these devices, at low elec tric fields, the electron multiplication occurs mainly in the latter h alf of the i region because of dead space effects. As the electric fie ld increases the multiplication behavior converges to that of the equi valent alloy. Our measurements show that the electron multiplication i n these structures never exceeds that of GaAs. A simple Monte Carlo si mulation suggests that the advantage obtained from the conduction band edge step down from AlxGa1-xAs to GaAs is offset by the energy loss v ia higher phonon emission in the AlxGa1-xAs layer. (C) 1997 American I nstitute of Physics.