Full text loading...
(a) Schematic illustration of MWNT- heterojunction device and a SEM image of the MWNT- interface. (b) Current-voltage plot of MWNT- devices showing the photovoltaic response under low intensity IR light . Inset: dark current-voltage characteristics on a linear scale; -axis is V and -axis is .
(a) Normalized photocurrent spectra (based on the intensity of IR Globar source) of the MWNT- devices with (red curve) and without (blue curve) LF and control SWNT- device (black curve). Inset: Tauc plot data at 300 K, which is used to determine the band gap of the CNTs. The band gap, (0.025 eV) of the MWNTs (15–30 nm diameters) is obtained via extrapolation to the zero crossing of the -axis. It is known that can be determined by extrapolation of the Tauc plot , where is the absorption) to the zero crossing of the axis for the absorption band edge of semiconductors. (b) Energy band diagram of MWNT- heterojunction based on Anderson model. Electron affinity, and conduction band offset, for MWNTs and are shown in the schematic.
(a) Time traces of photocurrent from MWNT- devices (sonication only: black curve, sonication and centrifugation followed by sediment extraction: red curve) under IR illumination with LF. The nanotubes deposited by spraying from the sediment fraction showed increase in the photocurrent response with respect to the samples without centrifugation. (b) Normalized photocurrent (amplitude of peak to peak current) as a function of frequency. The characteristic time of MWNT- photodiode is (at ) at peak to peak amplitude of 70.7% (3 dB reduction of photocurrent response).
Article metrics loading...