High-Field Electrical and Thermal Transport in Suspended Graphene

• Published in: Nano letters Vol. 13; no. 10; pp. 4581 - 4586
• Main Authors: Dorgan, Vincent E, Behnam, Ashkan, Conley, Hiram J, Bolotin, Kirill I, Pop, Eric
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 09.10.2013
• Subjects: Breakdown; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Devices; Electricity; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Graphene; Graphite; Graphite - chemistry; Heat transfer; Heat transmission; Humans; Lattice dynamics; Materials science; Nanostructures - chemistry; Particle Size; Phonons in low-dimensional structures and small particles; Physics; Saturation; Specific materials; Temperature; Thermal Conductivity; Thermal properties of condensed matter; Thermal properties of small particles, nanocrystals, nanotubes; thermal conductivity; Graphene; suspended; high-field; drift velocity; breakdown; Second order; Transport properties; Electric field effects; Graphite; High field; Breakdown; Thermal conductivity; Silicon; Phonon scattering; Operating conditions
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl400197w

We study the intrinsic transport properties of suspended graphene devices at high fields (≥1 V/μm) and high temperatures (≥1000 K). Across 15 samples, we find peak (average) saturation velocity of 3.6 × 107 cm/s (1.7 × 107 cm/s) and peak (average) thermal conductivity of 530 W m–1 K–1 (310 W m–1 K–1) at 1000 K. The saturation velocity is 2–4 times and the thermal conductivity 10–17 times greater than in silicon at such elevated temperatures. However, the thermal conductivity shows a steeper decrease at high temperature than in graphite, consistent with stronger effects of second-order three-phonon scattering. Our analysis of sample-to-sample variation suggests the behavior of “cleaner” devices most closely approaches the intrinsic high-field properties of graphene. This study reveals key features of charge and heat flow in graphene up to device breakdown at ∼2230 K in vacuum, highlighting remaining unknowns under extreme operating conditions.