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arXiv · 1702.02829

A graphene Zener-Klein transistor cooled by a hyperbolic substrate

W. Yang·S. Berthou·X. Lu·Q. Wilmart·A. Denis·M. Rosticher·T. Taniguchi·K. Watanabe·G. Feve·J. M. Berroir·G. Zhang·C. Voisin·E. Baudin·B. Plaçais
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Abstract

Engineering of cooling mechanisms is a bottleneck in nanoelectronics. Whereas thermal exchanges in diffusive graphene are mostly driven by defect assisted acoustic phonon scattering, the case of high-mobility graphene on hexagonal Boron Nitride (hBN) is radically different with a prominent contribution of remote phonons from the substrate. A bi-layer graphene on hBN transistor with local gate is driven in a regime where almost perfect current saturation is achieved by compensation of the decrease of the carrier density and Zener-Klein tunneling (ZKT) at high bias. Using noise thermometry, we show that this Zener-Klein tunneling triggers a new cooling pathway due to the emission of hyperbolic phonon polaritons (HPP) in hBN by out-of-equilibrium electron-hole pairs beyond the super-Planckian regime. The combination of ZKT-transport and HPP-cooling promotes graphene on BN transistors as a valuable nanotechnology for power devices and RF electronics.

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W. Yang, S. Berthou, X. Lu, Q. Wilmart, A. Denis, M. Rosticher, T. Taniguchi, K. Watanabe, G. Feve, J. M. Berroir, G. Zhang, C. Voisin, E. Baudin, B. Plaçais. 2017-02-09. A graphene Zener-Klein transistor cooled by a hyperbolic substrate. https://doi.org/10.1038/s41565-017-0007-9

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