Byproduct-free mass production of compound semiconductor nanowires: zinc phosphide. (30th May 2018)

• Record Type: Journal Article
• Authors: Chen, Yixi; Polinnaya, Rakesh; Vaddiraju, Sreeram
• Is Part Of: Materials research express. Volume 5:Number 5(2018)
• Publication Date: 2018-05-30
• Subjects: nanowires -- mass production -- byproduct-free synthesis -- self-catalysis -- chemical vapor deposition -- Zn3P2; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/aac41a
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: A method for the mass production of compound semiconductor nanowires that involves the direct reaction of component elements in a chemical vapor deposition chamber (CVD) is presented. This method results in nanowires, without the associated production of any other byproducts such as nanoparticles or three-dimensional (3D) bulk crystals. Furthermore, no unreacted reactants remain mixed with the nanowire product in this method. This byproduct-free nanowire production thus circumvents the need to tediously purify and collect nanowires from a mixture of products/reactants after their synthesis. Demonstration made using zinc phosphide (Zn3 P2 ) material system as an example indicated that the direct reaction of zinc microparticles with phosphorus supplied via the vapor phase results in the production of gram quantities of nanowires. To enhance thermal transport and achieve the complete reaction of zinc microparticles, while simultaneously ensuring that the microparticles do not agglomerate into macroscale zinc particles and partly remain unreacted (owing to diffusion limitations), pellets composed of mixtures of zinc and a sacrificial salt, NH4 Cl, were employed as the starting material. The sublimation by decomposition of NH4 Cl in the early stages of the reaction leaves a highly porous pellet of zinc composed of only zinc microparticles, which allows for inward diffusion of phosphorus/outward diffusion of zinc and the complete conversion of zinc into Zn3 P2 nanowires. NH4 Cl also aids in removal of any native oxide layer present on the zinc microparticles that may prevent their reaction with phosphorus. This method may be used to mass produce many other nanowires in a byproduct-free manner, besides Zn3 P2 .