Junction array carbon nanotube bolometer

Abstract

Vertically aligned arrays of multi-walled carbon nanotubes (MWNT forests) irradiated with low-intensity near-infrared laser exhibited bolometric response that became significant with decreasing temperature down from room to about 84 K. High responsivity of 42 V/W with signal bandwidth of about 2600 Hz was observed in the region with a surprisingly small temperature coefficient of resistance. This fact along with peculiar current dependences of material differential photoresistance can be explained by lifting Coulomb blockade in carbon nanotube junctions irradiated with light. A combination of significant bolometric response and nonlinear electrical transport are believed to be characteristic features of the nanostructured junction array system. Investigated material also revealed quite substantial noise with equivalent power of 3 * 10−6 WHz−½ that can be reduced by optimization of nanotube junction network in the forest structure.

Ordered nanoparticle arrays interconnected by molecular linkers: electronic and optoelectronic properties

“…Recently, it was shown that in the Coulomb blockade regime, the photoconductance can be understood in terms of a redistribution of the potential landscape in the nanoparticle array. 70,71 The I photo À V sd characteristics of such a nanoparticle array is non-linear as shown in Fig. 7(a).…”

Uncooled Carbon Nanotube Photodetectors

“…Many MWCNT bolometers have been reported, including MWCNT networks, [87,99] vertically aligned MWCNTarrays, [101] aligned MWCNT films [90] and MWCNT bundles with antenna structures. [75] Wu and coworkers reported a room temperature bolometric response (at a wavelength of 1.3 µm) for MWCNT films suspended on patterned SiO 2 /Si substrates.…”

Spray Coating of Two-Dimensional Suspended Film of Vanadium Oxide-Coated Carbon Nanotubes for Fabrication of a Large Volume Infrared Bolometer

“…Carbon nanotubes (CNTs) have been extensively studied for radiation detection because of their “darker than black” characteristic that enabled absorption of a wide range of the electromagnetic spectrum. − CNTs are preferred over conventional metal thin films for a radiation detector − because of the various limitations such as difficulty in miniaturization, − narrow wavelength interaction, susceptibility to delaminate by thermal stress generation, ,− thus resulting degradation in device performance. ,− Therefore, numerous studies emerged on fabricating devices to harness optical absorption efficiency of CNTs for various optical interactions and their nanoscale volume together with their extreme robustness to chemical, mechanical, and thermal stresses. − Among CNTs, single-walled CNTs (SWCNTs) due to strongly coupled excitons with quasi one-dimensional lattice demonstrated much enhanced bolometric photoresponse in both substrate-free (suspended) and unsuspended configurations. ,, Generally, heat capacity determines the response rate, and in the steady-state, the temperature increase in a bolometer is proportional to the absorbed power and inversely proportional to the thermal conductivity . Studies demonstrated that suspended CNT films reduce the thermal link to the environment and hence provide a significant enhancement of the bolometric photoresponse. , Itkis et al reported a large bolometric photoresponse of suspended SWCNT films with the temperature coefficient of resistance (TCR) of 1% at 330 K and 2.5% at 100 K, which is close to the vanadium oxide bolometer obtained at room temperature .…”