INVESTIGATION OF THE PRESSURE-DEPENDENCE OF SUBBAND TRANSITIONS IN ZNSE ZN1-XMGXSE QUANTUM-WELLS BY PLE/

Photoluminescence-excitation (PLE) measurements of wide ZnSe/Zn1-xMgxS e single quantum wells (SQW) are presented, performed under high hydro static pressure up to 4 GPa. The fully strained samples have been grow n by MBE on GaAs(0 0 1) substrates or (1 1 0) substrates. The well tra nsitions 1nH(1s) and 1mL(1s) with n = 1, 2, 3, 4, 5 and m = 1, 2 were recorded as well as excitonic signals from the barrier material at 2 K and their pressure dependence were determined. A cross-over between t he 11L and 13H, as well as between the 12L and 14H transitions, was ob served above 1.2 GPa. The transitions were assigned using a modified K ronig Penney model. The exciton binding energy was derived from the en ergy difference between the 11H(1s) and the 11H(2s) transitions. (C) 1 998 Elsevier Science B.V. All rights reserved.