Synthesis and optical properties in ZnSxSe1-x alloy nanowires

Keywords:
nanowires, alloy, ZnS, ZnSe

Abstract:
We successfully synthesized ZnSxSe1-x (0 x 1) alloy nanowires on Au-coated Si substrates by a pulsed-laser ablation process. The stoichiometric sintered ZnSxSe1-x targets, placed at the center of a quartz tube, were laser-ablated at a fluence of ~2J/cm2 (KrF excimer laser, 248nm) and then we could obtain well-developed ZnSxSe1-x nanowires at the down-stream side of the reaction tube. The synthesized nanowires have the diameter ranging from 50 to 200 nm and length attaining one hundred micrometer. X-ray diffraction analyses showed that ZnSxSe1-x nanowires have hexagonal wurtzite crystalline structure. The diffraction peaks were shifted toward the higher value of 2 theta as the value of x increases, which indicates that the lattice constant and unit cell volume scales linearly with the composition. From photoluminescence measurements, we found that the direct band gap of the nanowires also changes linearly with the composition, which means that the energy band gap could be systematically modulated in the spectral region from 2.66 to 3.50 eV. The ZnSxSe1-x nanowires have potential opto-electronic device applications such as photo-sensors, which can respond to the broad band of light from visible to UV excitation.

Nanotech 2008 Conference Program Abstract