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

A novel spray coating and transfer method is developed for fabricating a suspended bolometer of vanadium oxide-coated multiwalled carbon nanotubes (VCNTs). A parametric study was performed to evaluate the effect of the substrate, modulation frequency, and temperature on the bolometric performance and revealed that the performance of the bolometer solely does not depend on the substrate parameter but modulation frequency and bias current as a function of temperature also play a key attribute. The TCR (temperature coefficient of resistance) of the suspended VCNT bolometer is ∼-0.41%/K which is ∼486% higher than the reported suspended multiwalled CNTs at 300 K. Moreover, the suspended bolometer has a voltage responsivity of ∼67.42 ± 5.46 V/W (∼7.68 times that of unsuspended) at 200 K. Thus, the study presents an efficient method to develop the suspended bolometer that has not been realized so far to obtain much higher TCR and responsivity.