Vertically aligned graphene based non-cryogenic bolometer
We report the photoresponse of vertically aligned graphene upon IR irradiation at room temperature. Four probe measurements have shown electrical switching in I-V characteristics during pulsed IR irradiation. The photoresponse reported here for vertically aligned graphene (VAG) is much higher than carbon nanotube (CNT) samples. Our investigation has shown that such photoresponse arise solely due to bolometric effect, where the conductivity changes with temperature. The magnitude of the resistance of VAGs increases by ~ 2 fold for 6 0C increase in temperature. Also the Thermal Coefficient of Resistance (TCR) in this region is ~11%/K, which is the highest TCR value reported so far for any carbon nanomaterials.