Photoelectrical Characteristics of a C/CNx Multiwalled Nanotube


  • The authors acknowledge partial financial support from NSFC (90 206 049, 20 472 089, 20 421 101, 20 404 013, 20 527 001, 20 573 115, 50 673 093, 60 671 047), MOST, and CAS. YL acknowledges support from the Swedish Research Council and the Carl Trygger Foundation.


A nanotube diode fabricated from a single C/CNx multiwalled nanotube exhibits a large photocurrent and a large photovoltage under illumination. The current–voltage (I–V) characteristics of the diode indicate a clear rectification effect. By comparing the I–V characteristics of C, CNx, and C/CNx nanotube diodes, we show that the rectifying characteristics of the C/CNx diode arises from the molecular junction formed at the C/CNx interface where the C and CNx segments are chemically bonded. External radiation photochemically generates electrons and holes in the C/CNx nanotube, producing a large photocurrent because of the influence of the strong electric field in the vicinity of the C/CNx junction. These unique photoresponsive characteristics of C/CNx nanotube junction diodes points to potential applications such as photovoltaic devices and photodiodes.