▎ 摘　　要

A sensor using the photothermoelectric effect of graphene is anticipated as a candidate for infrared sensors that can operate at room temperature with fast response and high sensitivity. We investigate photothermoelectric detection and the signal-to-noise characteristics of a sensor with a simple metal-graphene-metal structure numerically and analytically and obtain an analytical expression giving the ideal value of specific detectivity D* for a sensor having an ideal potential distribution. It is found that the optimal sensor length is approximately three times longer than the cooling length and that the value of D* for such a sensor with typical cooling length is estimated to be as large as 10(6) cm root Hz/W. The sensor performance can be greatly enhanced by employing light-confining structures such as cavities and plasmon antennas, achieving D* above 108 cm root Hz/W. Published under an exclusive license by AIP Publishing.