Graphene-based terahertz photodetector by noise thermometry technique

Abstract

We report the characteristics of graphene-based terahertz (THz) photodetector based on noise thermometry technique by measuring its noise power at frequency from 4 to 6 GHz. Hot electron system in graphene microbridge is generated after THz photon pumping and creates extra noise power. The equivalent noise temperature and electron temperature increase rapidly in low THz pumping regime and saturate gradually in high THz power regime which is attributed to a faster energy relaxation process involved by stronger electron-phonon interaction. Based on this detector, a conversion efficiency around 0.15 from THz power to noise power in 4–6 GHz span has been achieved.

Photon-Assisted Shot Noise in Graphene in the Terahertz Range

“…1(d) [27]. This nonetheless confirms that noise measurements in graphene and other nanodevices can be used for THz detection [31,32].…”

Terahertz detection using mechanical resonators based on 2D materials

“…Previous work has taken advantage of graphene's linear band structure and the low heat capacity of singlelayer graphene. THz detection has been done via a plasmonic mechanism [11], by bolometric detection [10], and by noise thermometry [13]. A recent experiment [12] with graphene FET with dissimilar contact metals reached noise equivalent power (NEP) around 20 pW/Hz 1/2 operating at room temperature.…”

“…THz detection using graphene has aroused considerable interest [8][9][10][11][12][13]. Previous work has taken advantage of graphene's linear band structure and the low heat capacity of singlelayer graphene.…”