Dislocation-Driven Growth of Optical Waveguiding CdTe Nano-/Microwires

We report the growth of optical waveguiding CdTe nano-/microwires (NMWs) via chemical vapor deposition. By regulating the basic growth parameters during the chemical vapor deposition process, tailoring NMW architectures and crystallographic phases is enabled. For the first time, dislocation-driven growth of CdTe NMWs is observed. In contrast to Aucatalyzed zinc blende NMWs grown at a relatively low growth temperature through the vapor- liquid-solid process, wurtzite NMWs are obtained at a higher temperature by a screwdislocation-driven vapor-solid growth process. A classical crystal growth theory is used to show that 1D growth of these NMWs is enabled by the dislocation-provided self-perpetuating steps. The NMWs are characterized by scanning electron microscopy, high-resolution transmission copy. The results demonstrated an excellent single-crystal structure, smooth surface, and uniform geometry. Waveguiding properties of these NMWs are investigated in both theory and experiment. With diameters ranging from several hundred nanometers to several micrometers and length up to few millimeters, these NMWs show great potential in waveguiding and nonlinear optical applications.