A COMPARATIVE-STUDY OF ORDERED ALLOY AND RANDOM ALLOY QUANTUM-WELLS OF ZN1-XCDXSE ZNSE UNDER PRESSURE/

Excitonic transitions in random alloy and ordered alloy quantum wells of Zn1-xCdxSe/ZnSe are studied as a function of hydrostatic pressure a t 14 K using photoluminescence. A sample of bulk Zn1-xCdxSe is also st udied in the same pressure loading as the other two samples to determi ne the increase in the bandgap as a function of pressure. This simulta neous study has allowed us to isolate the pressure-induced changes due to quantization effects, as well as to study the differences between the random and ordered alloy quantum well systems. We find that the in fluence of ordering in these samples is evident at thicknesses of simi lar to 25 Angstrom, and less. We also find that a single period of the ordered alloy behaves like a quantum well, despite a large overlap of the wavefunction with the barrier and an extremely large confinement energy.