Optical Properties in ZnCdSe–ZnSe Multiple Quantum Wells

Abstract

The optical properties of Zn1-xCdxSe–ZnSe multiple quantum wells (MQWs) have been investigated. The MQWs samples exhibit five photoluminescence peaks under the 457.9 nm line of an Ar ion laser excitation at 77 K. Three of these bands are attributed to different exciton emission: the n=1 heavy–hole exciton transition, the n=1 light–hole exciton transition and n=1 heavy–hole exciton transition with the emission of two LO phonons. The room–temperature nanosecond switching property has also been studied in Zn1-xCdxSe–ZnSe MQWs F–P–type optical bistable device operation in reflection, in which their switching threshold and contrast ratio are about 47 kW/cm2 and 7:1, respectively. The origin of the major nonlinear mechanism for the optical switching property is due to the change of the refractive index caused by the effect of the excitonic saturating absorption effect in the ZnCdSe–ZnSe MQWs.