2017/02/28 by W. Yang, Wei Yang, S. Berthou +25
Engineering · Materials Science · Physics and Astronomy · #Bilayer graphene #Graphene #Graphene nanoribbons #Graphene research and applications #Phonon #Quantum tunnelling #Substrate (aquarium) #Thermal Radiation and Cooling Technologies #Thermal conductivity #Thermal properties of materials #Transistor #cond-mat.mes-hall
paper · pdf · doi:10.1038/s41565-017-0007-9
published as Nature Nanotechnology 13, 47 (2018) · 15 pages, 4 figures
openalex publication_date 2017/11/27 · openalex created_date 2017/12/04 · arxiv created 2018/04/25 · arxiv updated 2018/04/26 · openalex updated_date 2026/08/05
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.