Nano Research

Article Title

Novel photodetectors based on double-walled carbon nanotube film/TiO2 nanotube array heterodimensional contacts


Photodetectors, double-walled carbon nanotube (DWCNT) films, TiO2 nanotube arrays, heterodimensional contacts


A new kind of photodetector based on a double-walled carbon nanotube (DWCNT) film and a TiO2 nanotube array with hetrodimensional non-ohmic contacts has been fabricated. Due to the dimensionality difference effect, the DWCNT film/TiO2 nanotube array photodetector exhibits a much higher photocurrent-to-dark current ratio and photoresponse relative to an Au film/TiO2 nanotube array device, even at small bias voltage. The photocurrent-to-dark current ratio reached four orders of magnitude and a high photoresponse of 2467 A/W was found upon irradiation at 340 nm. Furthermore, the photosensitive regions could be extended into the visible range. The photocurrent-to-dark current ratio reached approximately three orders of magnitude upon irradiation at 532 nm, where the photon energy is much lower than the band gap of TiO2.

Graphical Abstract


Tsinghua University Press