QUANTUM-WELL EXCITONS IN AN ELECTRIC-FIELD - 2 VERSUS 3-DIMENSIONAL BEHAVIOR

Previous calculations have shown a transition between two dimensional and three dimensional behavior of excitons confined in a semiconductin g quantum well structure as a function of electric field. We here pres ent calculations of the exciton binding energy as a function of electr ic field using a two parameter variational wave function of the form u sed in the absence of the electric field by Matsuura and Shinozuka. Ou r calculations were performed using a finite potential barrier model f or the confinement of the exciton in the quantum well. The results of our calculations confirm the validity of the conclusion that the varia tional exciton wave function goes from being of a purely 2D hydrogenic type at small well widths and/or low electric fields to a 3D hydrogen ic type in wide wells and/or high electric fields. (C) 1995 Academic P ress Limited