Catalytic Growth of Germanium Oxide Nanowires, Nanotubes, and Germanium Nanowires: Temperature-Dependent Effect

Abstract

One-dimensional GeO 2 and Ge nanostructures, including nanotubes, nanowires, and branched nanowires, were synthesized using Au as catalysts. White products of GeO 2 and brown products of Ge were fabricated at temperature regions of 500-600 and 300-400 °C, respectively. For the first time, we report the formation of single-crystalline GeO 2 nanotubes and branched nanowires. Detailed growth mechanisms of the nanowires, nanotubes, and branched nanowires are presented. Fabrication of one-dimensional nanostructures with different configurations and compositions simultaneously from a single precursor enables the diversity of nanotube/ nanowire synthesis, as well as their potential applications in nanoscale photonic and electronic devices.

Growth of GaN nanotubes by halide vapor phase epitaxy

“…Similar growth models for nanotubes have previously been suggested for other materials such as GeO 2 [21] , InP [22] and MgO [23].…”

The temperature dependence of 1D germanium nanostructures grown in a small-diameter quartz tube cavity by vapor deposition

“…It is known that VLS growth of 1D nanostructures is directly affected by substrate materials [17], precursor pressure [18], growth temperature [19], catalyst positions [20], and some other factors. Noticeably, substrate temperature is believed to be a vital factor to control the morphologies of products [19,21,22], which have attracted much research interest [14,23,24]. But the temperature dependent relations of Ge nanostructures are not consistent in these reports [14,23,24].…”

“…Noticeably, substrate temperature is believed to be a vital factor to control the morphologies of products [19,21,22], which have attracted much research interest [14,23,24]. But the temperature dependent relations of Ge nanostructures are not consistent in these reports [14,23,24]. The possible reason might be the different precursor, carrier gas, furnace temperature, or precise experimental methods.…”

Submicron rectangular hollow tube crystals of rutile-type GeO2

“…Moreover, it is a chemical analogue of silica, SiO 2 , which is the main component of various types of glass that is also used in optical and machining technology. In light of this background, several groups have attended to fabricate nano-and meso-sized crystals of GeO 2 [3][4][5][6][7].…”

“…quartz-like-type, rutile-type, CaCl 2 -type, a-PbO 2 -type, and pyrite-type) [8][9][10]. Among these polymorphs, only single crystals with a quartz-like structure have been reported thus far [3][4][5][6][7]11], although rutile-type GeO 2 is thermodynamically stable in an ambient condition. The reason for this can be clearly understood from the pressure-temperature phase diagram of GeO 2 (see Fig.…”