University of Maryland,
Keywords: flexible electronics, carbon semiconductors, solution processing, single-walled carbon nanotubes, tube^2
Summary:Single-walled carbon nanotube semiconductors have the electrical and mechanical properties that may enable next-generation printed and flexible electronics. However, nanotubes are cut to short pieces (typically less than 1 μm) by sonication during solution processing, which downgrades their otherwise extraordinary properties. Another challenge is that these atomically-thin materials are prone to chemical attack because all of the constituent atoms are exposed. In this talk, I will discuss recent progress in addressing these challenges and some new opportunities that arise. Particularly, I will introduce a technique from my lab called “superacid-surfactant exchange (S2E)” which allows for non-destructive dispersion and scalable sorting of ultralong nanotubes in aqueous solutions. The length of the isolated nanotubes readily reaches 10 μm, with a narrow distribution. I will further show that these ultralong nanotubes can be sorted by electronic type to attain mobility exceeding 90 cm2 V-1 s-1 in fabricated thin film transistors. I will also discuss our progress in the synthesis of a tube-in-a-tube semiconductor (Tube^2) that uniquely combines both surface functionalities and protected electronic properties.