Thermal stability and lasing of US nanowires coated by amorphous silica

The process of optically pumped lasing of CdS nanowires (NWs) at low temperature was analyzed. Single-crystalline CdS NWs were prepared by a hydrothermal route and were coated with a uniform silica layer to yield coaxial structures. Thermal analysis (DTA/TGA) and phase analysis X-ray diffraction (XRD) was used to examine the thermal stability of the NWs. It was found that the high-temperature stability of the silica-coated NWs improved significantly as their thermal degradation temperature was greatly increased. It was also found that photoluminescence (PL) emission of CdS NWs were enhanced after coating with amorphous silica. Stimulated emission for the coated NWs under high-intensity optical excitation was observed at room temperature, which showed that high-stability NWs have potential applications in photonic and optoelectronic fields.