ZnO nanowires by pulsed laser vaporization: synthesis and properties

Synthesis and optical spectroscopic studies of semiconducting cadmium sulfide nanowires

Optical properties of cadmium sulfide nanowires of 50-100 nm diameter prepared by the pulsed-laser vaporization method have been studied using photoacoustic, UV-Vis, Raman, and photoluminescence spectroscopy. The photoacoustic (PA) technique yielded clean spectra with a steeper absorption edge for as-prepared opaque semiconducting CdS nanowires when compared to the corresponding conventional optical absorption spectra. The PA signal intensity was also significantly higher for nanowires. The Raman spectrum revealed increased exciton-longitudinal-optical-phonon coupling. The appearance of a narrow photoluminescence peak at 491 nm (FWHM approximately 9 nm) and the absence of emission above 500 nm demonstrate the high quality of nanowires. High-resolution transmission electron microscopy showed excellent ordering of the atoms in the [001] planes perpendicular to the growth direction.

Highly sensitive ZnO nanowire CO sensors with the adsorption of Au nanoparticles

In this study, the growth of high density single-crystalline ZnO nanowires on patterned ZnO:Ga/SiO(2)/Si templates was reported. We also adsorbed Au nanoparticles onto nanowire surfaces and fabricated ZnO nanowire CO sensors. With 50 ppm CO gas, it was found that we could enhance the device sensitivities at 350 °C from 4.2% to 46.5% by the adsorption of Au nanoparticles. It was also found that measured sensitivities were around 30%, 37%, 46.5% and 53% when concentration of the injected CO gas was 5, 20, 50 and 100 ppm, respectively.

Single-crystalline branched zinc phosphide nanostructures: synthesis, properties, and optoelectronic devices

Hierarchical tree-shaped nanostructures, nanobelts, and nanowires of Zn3P2 were synthesized in a thermal assisted laser ablation process. All nanostructures are tetragonal phased Zn3P2 with excellent crystallinity and are free from an oxidization layer according to electron microscopy and X-ray diffraction analyses. Optical measurement revealed a strong absorption from the ultraviolet to near-infrared regions. Optoelectronic devices fabricated using individual nanowires demonstrate a high sensitivity and rapid response to impinging light. A crossed heterojunction of an n-type ZnO nanowire and a p-type Zn3P2 nanowire has been characterized, and it offers a great potential for a high efficient spatial resolved photon detector.