Indirect excitons and double electron-hole layers in a wide single GaAs/AlGaAs quantum well in a strong electric field

The recombination spectra of indirect excitons and double electron-hole layers in a wide single quantum well in an electric field are studied. It is found that electrons and holes in the wide well become spatially separated in a sufficiently strong electric field. This leads to a substantial reorganization of the radiative recombination spectrum and to a significant increase in the carrier lifetime. It is shown that the total charge of the electron-hole system can be changed by varying the photoexcitation frequency and the applied electric field, thus passing from the neutral case of indirect excitons to the case of charged double electron-hole layers. The concentration of excess carriers in the well is measured as a function of the electric field strength. The behavior of the excited states of indirect heavy-hole and light-hole excitions is studied for a neutral excitonic system in a strong electric field. It is shown that the electric-field dependences allow the excited states of indirect excitons with a light hole to be distinguished from the excited states with a heavy hole.