Dimensionality transformation of the exciton state in quantum wells with asymmetric barriers

Under the conditions of 2-3D transformation of one-particle states, the dep endence of exciton binding energy E-ex on the well width h has been theoret ically studied for quantum structures with barriers of asymmetric height, I t is shown that the contribution of one-particle continuous spectrum states to the exciton becomes considerable when the inverse exciton Bohr radius 1 /a(b) is comparable to the value of wavevector k(c) critical for 2-3D trans formation. The lack of coincidence between electron and hole k(c) values le ads to a complicated shape of the E-ex (h) dependence with a minimum at int ermediate Values of It. The minimum value of E-ex appears to be less than t hat of the 3D exciton binding energy. The behaviour of the exciton PLE peak position is investigated for an asymmetric structure under the influence o f an external electric field.