Exciton energies as a function of electric field: Confined quantum Stark effect

Abstract

We have performed a variational calculation of the exciton binding energy as a function of electric field in a semiconducting quantum-well structure using a three-dimensional (3D) hydrogenic trial wave function and compared our results with earlier calculations in which a 2D hydrogenic trial wave function was used. Our results yield larger exciton binding energies for wide wells and strong electric fields. We find that the crossover between 2D and 3D behavior occurs at a critical well width which is of the order of the exciton Bohr radius in zero field and which decreases with increasing electric field. © 1993 The American Physical Society.