Exciton Energies as a Function of Electric Field in Quantum Wells Finite Potential Barrier Case

Abstract

AbstractA previous variational calculation of the exciton binding energy as a function of electric field in a semiconducting quantum well structure using a 3D hydrogenic trial wave function is extended to the case where the confining potential barrier is finite in height. The results are compared with those obtained for the same case using a 2D hydrogenic trial wave function. The results yield larger exciton binding energies for wide wells and strong electric fields. It is found 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. It is also found that decreasing the height of the barrier decreases the binding energy of the exciton, as expected.