SUBBAND STRUCTURE AND EXCITONIC BINDING OF GRADED GAAS GA1-XALXAS QUANTUM-WELLS UNDER AN ELECTRIC-FIELD/

The effects of an applied electric field on subband energies and excit onic binding for a graded GaAlAs quantum well are calculated variation ally within the effective mass approximation. The very sensitive depen dence of subband energies on the applied field is calculated using a m odel potential profile and exact electron and hole wavefunctions. Our calculations have revealed the dependence of the energy shifts of subb ands, and excitonic binding on the field direction in the graded quant um well. This permits control over tunneling which could be desirable for some applications. (C) 1998 Academic Press Limited.