We examine mobility and saturation velocity in graphene on SiO2 above roomtemperature (300-500 K) and at high fields (~1 V/um). Data are analyzed withpractical models including gated carriers, thermal generation, "puddle" charge,and Joule heating. Both mobility and saturation velocity decrease with risingtemperature above 300 K, and with rising carrier density above 2x10^12 cm^-2.Saturation velocity is >3x10^7 cm/s at low carrier density, and remains greaterthan in Si up to 1.2x10^13 cm^-2. Transport appears primarily limited by theSiO2 substrate, but results suggest intrinsic graphene saturation velocitycould be more than twice that observed here.
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机译：我们在高于室温（300-500 K）和高场（〜1 V / um）的条件下研究了SiO2上石墨烯中的迁移率和饱和速度。使用包括门控载流子，热量产生，“熔池”装料和焦耳热的实用模型分析数据。迁移率和饱和速度都随着温度的升高而降低，温度高于300 K，载流子密度高于2x10 ^ 12 cm ^ -2。低载流子密度下的饱和速度> 3x10 ^ 7 cm / s，直到1.2x10时仍高于Si ^ 13厘米^ -2。传输似乎主要受到SiO2衬底的限制，但结果表明，固有的石墨烯饱和速度可能是此处观察到的两倍以上。
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