Optical properties of quantum wells with a field-effect-induced lateral superlattice

Abstract
A new developed stacked gate technique and a special MBE-grown quantum well structure is used to investigate the optical properties of a quantum well in a field effect induced lateral superlattice potential. Gate voltages applied at two different gates allow to tune both the superlattice potential amplitude as well as the energetical position with respect to the Fermi-energy. The luminescence and luminescence excitation spectra show a strong dependence on these voltages. At certain gate voltage configurations electrons are filled into the minima of the lateral potential and form an array of quasi one-dimensional electron channels. At this point the luminescence splits into distinct peaks reflecting the lateral separation of photo excited electrons and holes. Excitation measurements illustrate the existence of occupied electron channels and unoccupied barriers between them.