Quantum Scattering Time and Its Implications on Scattering Sources in Graphene

Authors

• X. Hong, University of Nebraska–LincolnFollow
• K. Zou, Pennsylvania State University
• J. Zhu, Pennsylvania State University

Document Type

Article

Date of this Version

2009

Citation

Physical Review B (2009) 80: 241415®

Comments

Used by permission

Abstract

We determine the quantum scattering time T_q in six graphene samples with mobility of 4 400<μ <17 000 cm² /V s over a wide range of carrier density (1.2<n<6X10¹²/cm2). T_q derived from Shubnikov–de Haas oscillation ranges ~25–74 fs, corresponding to a single-particle level broadening of 4.5–13 meV. The ratio of the transport to quantum scattering time T_t /T_q spans 1.5–5.1 in these samples, which can be quantitatively understood combining scattering from short-ranged centers and charged impurities located within 2 nm of the graphene sheet. Our results suggest that charges residing on the SiO₂ surface play a dominant role in limiting carrier mobility in current samples.