Nonlinear transport properties in multiwall carbon nanotube heterojunctions

Electronic transport properties of a heterostructure junction made of two different multiwall carbon nanotubes are studied. Independent measurement of the current-voltage characteristics of each nanotube revealed that both of them were lightly p-doped semiconductors with energy gaps whose magnitudes are widely different from each other. The current-voltage characteristics measured across the heterojunction show reproducible rectifying diode behavior. The forward bias current across the heterojunction increases rapidly with the application of a positive gate bias voltage, implying an n -type gate response.