晶元尺寸基底上单一手性单壁碳纳米管的生长

Chirality-specific growth of single-walled carbon nanotubes (SWNTs) is one of the main challenges in the field and also the key issue in the development of advanced applications. This project intends to develop the strategy for wafer-scale growth of chirality-specific SWNTs based on deep understanding about the growth mechanism. We will develop a series of intermetallic compound catalysts, establish methods to disperse and pattern catalysts on substrates, adjusting the growth condition, and eventually obtain SWNTs and their arrays with identical chiralities. By characterizing the step structure of the nanocrystals and the interface between SWNT and the catalyst, and performing DFT simulation, the importance of structure match between SWNT and catalyst can be revealed. The influence of carbon feeding in CVD process on the chirality distribution of SWNTs is another important issue. With these results, we will analyze the mechanism of the chirality selective growth based on fundamental theories of thermodynamics and kinetics. Our target is obtaining SWNT samples on 4-inch wafers with chirality purity higher than 98% and content of semiconducting tube higher than 99.5%. Integrated circuits with more than 100 devices will be built and the performance will be tested.

单壁碳纳米管的手性可控生长是碳纳米管研究中的核心问题，也是其应用的基础和关键。本项目拟在深入理解反应机制的基础上发展晶元尺寸上高纯度单一手性碳纳米管的生长方法。开发金属间化合物催化剂，发展它们的制备和排布方法，调控化学气相沉积条件，生长单一手性的单壁碳纳米管及其阵列样品。通过对催化剂与碳纳米管界面的结构表征和环境透射电镜下原位跟踪碳纳米管生长过程，结合密度泛函计算，揭示催化剂结构与碳纳米管手性匹配的关系；并考察供碳速度等动力学因素对手性分布的影响，在此基础上构建单壁碳纳米管手性选择性生长的机制，并以此指导催化剂和生长条件的设计。最终实现4吋晶元基底上手性纯度高于98%，半导体管含量高于99.5%的碳纳米管生长。并构筑不少于100个晶体管的集成电路，测试其性能。

本项目围绕晶圆尺寸基底上高纯度单壁碳纳米管的制备开展研究，主要取得了以下进展：发展了利用生物分子组装多酸团簇可控制备Co7W6纳米晶及通过前驱体可控组装在晶元尺寸基底上制备均匀排布、尺寸均一的Co7W6催化剂的方法；发展了基于原位环境球差电镜和原位同步辐射谱学技术的方法，揭示了Co7W6在单壁碳纳米管手性选择性生长过程中的模板作用；在硅片基底上实现了（14,4）型碳纳米管含量>97%、半导体性管含量99%的直接生长，在蓝宝石基底上实现了（18,7）型碳纳米管含量90%、半导体性管含量99%的单一手性单壁碳纳米管阵列的直接生长；使用双水相萃取法获得了（6,5）手性纯度为98%，半导体性管纯度99.9%的单壁碳纳米管，并在4吋晶元基底上均匀沉积；使用聚咔唑类高分子获得了半导体性纯度大于99.992%的单壁碳纳米管，并在4吋晶元基底上均匀沉积；构筑了由100个碳纳米管场效应晶体管组成的逻辑电路，验证了其性能。本项目已发表基金资助标注的学术论文43篇，申请专利10项，获得专利授权6项，在国际、国内学术会议上做大会、主题和邀请报告四十余次，获教育部自然科学一等奖和国家自然科学二等奖。