High Current Density and Low Thermal Conductivity of Atomically Thin Semimetallic WTe2

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• 作者：Michal J. Mleczko ; Runjie Lily Xu ; Kye Okabe ; Hsueh-Hui Kuo ; Ian R. Fisher ; H.-S. Philip Wong ; Yoshio Nishi ; Eric Pop
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：August 23, 2016
• 年：2016
• 卷：10
• 期：8
• 页码：7507-7514
• 全文大小：487K
• 年卷期：0
• ISSN：1936-086X

文摘

Two-dimensional (2D) semimetals beyond graphene have been relatively unexplored in the atomically thin limit. Here, we introduce a facile growth mechanism for semimetallic WTe₂ crystals and then fabricate few-layer test structures while carefully avoiding degradation from exposure to air. Low-field electrical measurements of 80 nm to 2 μm long devices allow us to separate intrinsic and contact resistance, revealing metallic response in the thinnest encapsulated and stable WTe₂ devices studied to date (3–20 layers thick). High-field electrical measurements and electrothermal modeling demonstrate that ultrathin WTe₂ can carry remarkably high current density (approaching 50 MA/cm², higher than most common interconnect metals) despite a very low thermal conductivity (of the order ∼3 Wm^–1 K^–1). These results suggest several pathways for air-stable technological viability of this layered semimetal.