EXCITONIC PROPERTIES IN ZNSE ZNSXSE1-X STRAINED-LAYER SUPERLATTICES BY ONE-PHOTON AND 2-PHOTON SPECTROSCOPY/

Excitonic properties of ZnSe/ZnS0.18Se0.82 Strained-layer superlattice s have been investigated by means of one- and two-photon absorption sp ectroscopy. Heavy- and light-hole excitons associated with n = 1,2 sub bands have been observed and experimental evidence of 2s states in the se systems has been obtained. Experimental exciton transition energies have been found to be in good agreement with theoretical predictions considering strain and confinement effects. The different selection ru les governing linear and nonlinear absorption processes have been veri fied and some violations of them have been observed. Furthermore, exci ton binding energy has been measured and compared with the result of a recent theoretical model.