Multiwall nanotubes with intramolecular junctions (CNx/C): Preparation, rectification, logic gates, and application.

We prepared a large quantity of multiwall nanotubes with intramolecular junctions (CN_x/C) by pyrolysis of iron phthalocyanine with or without an inlet of ammonia gas. The nanotubes consist of two sections, one section made of carbon nitride featuring bamboo-like structure and the other one made of carbon featuring empty hollow cylinder structure, and thus the intramolecular junctions were formed in the middle as a result of being doped or undoped with nitrogen. Nanodiode based on a single CN_x/C junction shows reproducible rectifying behavior with a rectification ratio of 1.3×10³ at ±2 V. In addition, the nanodiode demonstrated as a half-wave rectifier worked at an input sine wave of 1 kHz. Two CN_x/C junctions were configured together to exhibit functions of OR and AND logic gates. Moreover, after substituting the wave-detection silicon diode in common transistor radio set with our nanodiode, the radio set still worked normally, representing an important step toward the potential application for nano-scale devices. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]