Time-resolved x-ray-excited optical luminescence characterization of one-dimensional Si–CdSe heterostructures

The authors have monitored the optical luminescence from one-dimensional Si–CdSe nanoheterostructures as a function of x-ray energy at the Se L3 edge (∼1430eV). The wires consist of a diamond Si core encased in a wurtzite CdSe sheath. The time-resolved luminescence spectrum consists of a short-lifetime band centered at 637nm and a long-lived band at 530nm. By monitoring the intensities of these bands following excitation of a Se 2p3∕2 electron, the authors are able to show that the 637nm band is associated with the CdSe sheath while the 530nm band emanates from the Si core.