Solution-Based Assembly of Large-Scale, Unidirectionally-Aligned Carbon Nanotubes for High-Performance Transistors

Central to many proposed electronic device-based applications of carbon nanotubes (CNTs) is the development of assembly methods that enable organization of these nanoscale building blocks over large areas with controlled orientation and density. In this talk, we will present a novel solution-based technique that combines spin assembly and molecular patterning for preparing large-scale, ultrathin CNT films with unidirectional alignment and controlled density. Guided by our simulation studies of particle adsorption to investigate both effects of the hydrodynamic force (spin rate) and surface interaction force (CNT-molecules), we have assembled well-ordered, unidirectionally-aligned CNTs over the wafer scale and directly integrated them as thin-film transistors (TFTs) that show promising device characteristics with large on/off ratio and high mobility. The scalable solution-based process for large-scale assembly of well-aligned CNT thin films can lead to many exciting applications ranging from large-scale, highly sensitive biological/chemical nanosensors to large-area flexible displays and solar cells.