Laser-Assisted Growth of t-Te Nanotubes and their Controlled Photo-induced Unzipping to ultrathin core-Te/sheath-TeO2 Nanowires

Abstract

One dimensional (1D) nanostructures of semiconducting oxides and elemental chalcogens culminate over the last decade in nanotechnology owing to their unique properties exploitable in several applications sectors. Whereas several synthetic strategies have been established for rational design of 1D materials using solution chemistry and high temperature evaporation methods, much less attention has been given to the laser-assisted growth of hybrid nanostructures. Here, we present a laser-assisted method for the controlled fabrication of Te nanotubes. A series of light-driven phase transition is employed to controllably transform Te nanotubes to core-Te/sheath-TeO2 and/or even neat TeO2 nanowires. This solid-state laser-processing of semiconducting materials apart from offering new opportunities for the fast and spatially controlled fabrication of anisotropic nanostructures, provides a means of simultaneous growing and integrating these nanostructures into an optoelectronic or photonic device.

Te hexagonal nanotubes: formation and optical properties

“…The hetero-interface nucleation made Te atom more easily to deposit on the surface of the template. The most active site for Te atom is along \0001[ direction due to the driving force of free energy [37][38][39]. In our experiment, the guiding effect of the surfactant template is not strong enough to change its growth direction, so Te atom is more easy to grow on the axial direction along \0001[.…”

Photo-induced oxidation and amorphization of trigonal tellurium: A means to engineer hybrid nanostructures and explore glass structure under spatial confinement

“…Visible light illumination of t-Te surfaces results in a variety of nano-structuring phenomena as have been reported elsewhere. 18 The formation of t-Te nanotubes that are disintegrated into t-Te/a-TeO 2 core/sheath nanowires, such as that shown in the TEM Fig. 2(a), takes place at high power densities.…”

“…5 In the present article, we report the results of photoinduced processing of crystalline trigonal Te (t-Te) using cw lasers operating at the visible wavelength spectral range as recently demonstrated elsewhere. 18 It is shown that irradiation causes photo-oxidation and amorphization of t-Te. The time-dependent kinetics of these processes is explored as a function of laser fluence.…”

Structural and Photoconductivity Properties of Tellurium/PMMA Films

“…In the inset , the maximum photocurrent obtained for each cycle, I phmax, is plotted as a function of light power density F According to refs. [6,23,28], the origin of photoconduction in this material may be attributed to the coexistence of Te and TeO2 phases due to the partial oxidation of Te grains as demonstrated by XRD analysis.…”

“…For example, Rao et al [14] reported controlled synthesis of Te nanorods, nanowires, nanobelts, and related structures by the disproportionation of NaHTe in different solvents, Xia et al [15,16] prepared uniform Te nanowires and nanotubes through the reduction of H6TeO6 by N2H4H2O or ethylene glycol in refluxing process, and Qian's group produced a series of 1D Te nanostructures including nanowires, nanobelts, and nanotubes via hydrothermal synthesis [17][18][19][20]. Recently, Zhu et al [21] presented an ultrasonic-assisted solution-phase approach for the fabrication of tellurium bundles of nanowhiskers, Sen et al [22] synthesized Te nanostructures by physical vapor deposition, and Vasileiadis et al demonstrated that a controlled fabrication of Te nanotubes can be carried out by irradiating bulk elemental Te with continuous wave lasers emitting in visible range for short exposure time [23].…”