Tailored polarization of optical propagation in heterostructured nanowires

摘要

Nanowires comprising a metal (Au) segment and a semiconductor segment (CdSe) were grown through an electrochemical process that allows the shape of the interface between the materials to be abrupt (planar) or to be tailored to form off-axis conical profiles. Polarized light was used to excite plasmons in the exposed end of the Au segment, and emission was studied at the Au:CdSe interface and at the distal end of the nanowire. Both the relative intensities of the emissions and the polarizations of the light from the distal end were correlated with the shapes of the interfaces. It was shown that the emission intensity and the degree of polarization were controlled by the interface shape. Finite difference time-domain studies of different interface shapes support the experimental conclusions.