Electrical characterization of single-walled carbon nanotube (SWCNT) microbolometers
A single-walled carbon nanotube (SWCNT)-based microbolometer was fabricated. The bolometer temperature coefficient of resistance (TCR) was obtained by measuring current-voltage (IV) characteristics from 20°C to 100°C using a four-point probe measurement set-up. The responsivity and the time constant were measured by applying an AC voltage from 1 Hz to 10 MHz and determining the output voltage over the given frequencies. The measured TCR was -1.1 %/K. A very high responsivity and extremely fast time constant were 49.9 kV/W and 400 ns, respectively. We attribute the very good performance of our microbolometer to the semiconducting nature of SWCNT, the low thermal conductance of the oxide layer, and the geometry of the electrodes.