Band Engineering of Carbon Nanotubes for Device Applications

Summary Carbon nanotubes (CNTs)—especially single-walled CNTs—are promising for device applications. Although CNTs have excellent intrinsic properties, their diverse band structures bring difficulties to improving the performances of CNT-based devices. Therefore, band engineering is necessary. For diverse electrical properties, selective enrichment of CNTs with specific electrical properties is essential for determining their corresponding application fields. For a certain band structure, methods such as doping can be used to slightly tune the energy bands of CNTs and make them more suitable for specific devices. Additionally, for some intrinsic limitations, construction of heterostructures with other functional materials is an effective way to tune the carrier transport at the interface and broaden the application range of CNTs. In this review, we discuss in detail the band engineering of CNTs and corresponding device applications from the respect of both microscopic and macroscopic devices. We present an outlook that controlled synthesis will determine the future applications and proper manufacture will improve the application qualities.