ELECTRON-HOLE SEPARATION IN A 2-DIMENSIONAL ELECTRON-SYSTEM INDUCED BY ELECTRIC-FIELDS

Electric-field-induced separation of electrons and holes in a two-dime nsional electron system us demonstrated in a single-side-doped GaAs/Ga AlAs quantum well structure. The separation is manifest in the quantum -confined Stark shift and also in a reduced electron-hole overlap that produces a large increase in the radiative recombination time. These effects were produced either by applying a gate voltage or by changing the internal Hartree electric field via changing the electron density . The observed order-of-magnitude lifetime increase agrees quantitativ ely with results of self-consistent calculations of the wavefunction o verlaps. Copyright (C) 1996 Elsevier Science Ltd