Evaluating defects in solution-processed carbon nanotube devices via low-temperature transport spectroscopy.

Abstract

We performed low-temperature electron transport spectroscopy to evaluate defects in individual single-walled carbon nanotube (SWNT) devices assembled via dielectrophoresis from a surfactant-free solution. At 4.2 K, the majority of the devices show periodic and well-defined Coulomb diamonds near zero gate voltage corresponding to transport through a single quantum dot, while at higher gate voltages, beating behavior is observed due to small potential fluctuations induced by the substrate. The Coulomb diamonds were further modeled using a single electron transistor simulator. Our study suggests that SWNTs derived from stable solutions in this work are free from hard defects and are relatively clean. Our observations have strong implications on the use of solution-processed SWNTs for future nanoelectronic device applications.