Template Assisted Growth of 1D Heterostructures

该项目旨在合成一维vdW双层和异质结构，其组成壁具有定义的莫尔图案（通过选择手性控制）。 结构明确的单壁碳纳米管（SWCNT）将用于碳或氮化硼的内壁和外壁的模板生长。 在工作包1（WP 1）中，将使用称为水两相萃取（ATPE）的方法来制备单手性SWCNT，包括金属，半导体和左手和右手物质，直径为1.4 - 1.5 nm。这些将被填充C60以形成豆荚结构，并在高温下转化为双壁碳纳米管（DWCNT）。 由外壁提供的几何约束将减少生长期间可能的内壁的数量，并且预测外壁甚至可以有利于单个手性内壁的形成。 在WP 2中，使用硼前体的封装的互补工艺将用于产生1D氮化硼/碳异质结构。 或者，碳纳米管的外表面将用于模板直接生长氮化硼外壁，并且来自WP 1的手性控制的DWCNT将转化为氮化硼。 通过这种方式，将获得新的见解，内/外壁在定义其对应物的原子结构中的作用，并将使一维纳米结构中可控莫尔图案的研究成为可能。 该项目将通过测量光致发光和拉曼光谱学中相对于单壁物种的光谱位移，以及通过在低温下进行电子测量以探测超导性等新现象，来研究结构限定的壁之间的光学和电子耦合。

This project aims to synthesize 1D vdW bilayers and heterostructures with defined moiré pattern (controlled by selection of chirality) of the constituent walls. Structurally well-defined single-walled carbon nanotubes (SWCNTs) will be used to template the growth of inner- and outer-walls of either carbon or boron nitride. In work package 1 (WP1), a process known as aqueous two phases extraction (ATPE) will be used to prepare mono-chiral SWCNTs, including metallic, semiconducting and left and right-handed species, with a diameter of 1.4 – 1.5 nm. These will be filled with C60 to form a peapod structure and converted to a double-walled carbon nanotube (DWCNT) at high temperature. Geometrical constraints provided by the outer-wall will reduce the number of possible inner-walls during growth and it is predicted that the outer- wall may even favor the formation of a single chiral inner-wall. In WP2 a complementary process using the encapsulation of boron precursors will be used to create a 1D boron nitride/carbon heterostructure. Alternatively, the external surface of the carbon nanotube will be used to template the direct growth of an outer-wall of boron nitride, and chirality controlled DWCNTs from WP1 will be converted to boron nitride. In this way, new insights will be gained into the role of the inner/outer-wall in defining the atomic structure of its counterpart and a study of controllable moiré patterns in 1D nanostructures will be enabled. This project will investigate the optical and electronic coupling between structurally defined walls by measuring spectral shifts relative to single walled species in photoluminescence and Raman spectroscopy and by making electronic measurements at low temperature to probe new phenomena such as superconductivity.