ELECTRON-ESCAPE FROM SELF-ASSEMBLED INAS GAAS QUANTUM-DOT STACKS/

Capacitance-voltage characteristics have been measured at various freq uencies and temperatures for a Schottky barrier structure containing t hree sheets of self-assembled InAs quantum dots in an n-GaAs matrix. B y changing the frequency of the measuring signal at fixed temperature, it is possible to control the ratio between the thermionic and the tu nnel contributions to the electron escape from the quantum dots. An ap plied magnetic field reduces the thermionic emission rate and increase s the importance of the tunnel part of escape of electrons from the do ts due to the deepening of electron level in the dots by Landau quanti zation in the GaAs conduction band. (C) 1998 Elsevier Science B.V. All rights reserved.