Thermal management function of graphene under cryogenic temperature

Abstract The thermal management function of high-quality graphene, which is expected to maximize in-plane thermal conductivity at cryogenic temperature, was demonstrated by cryogenic transmission electron microscopy (cryo-TEM) equipped with electron energy loss spectroscopy (EELS). Vitreous ice, observed under the cryo-TEM, suffers from electron beam irradiation, and gradually becomes thinner by sublimation. The ice thickness decreases exponentially with respect to the irradiation time of electron beam with and without graphene, according to the time series of thickness measurement by EELS. Direct contact between graphene and ice effectively dissipates the heat of the ice through graphene, which significantly suppresses the sublimation behavior. The heat dissipation by graphene is effective for thinner ice rather than thicker one. The lifespan of ice on graphene against electron beam irradiation extends to about 40%, showing substantial improvement compared to that without graphene. The graphene provides a new stream for effective thermal management in cryo-TEM analysis.