کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5432029 | 1508829 | 2017 | 5 صفحه PDF | دانلود رایگان |
We report a new method of ion implantation for hole doping of graphene in which a layer of polymethyl methacrylate (PMMA) is used as a stopping layer to control the B-ion distribution in the graphene layer. This method is very useful for graphene doping in many aspects because it employs the ion energy comparable to what is commercially used in the semiconductor processes and strongly enhances the doping effect in contrast to the previous studies, resulting from B-ions-induced gating effect. PMMA/graphene/Cu-foil stacks were implanted with 35Â keV Bâ ions to nominal fluences (ÏB) of 0.5-50Â ÃÂ 1010Â cmâ2Â at room temperature. The electron/hole mobilities are sharply reduced by doping at ÏBÂ =Â 0.5Â ÃÂ 1010Â cmâ2, but above this, they increase with increasing ÏB, as estimated from the Dirac curves. The Raman data and theoretical considerations suggest that the electrical properties of the B-doped graphene are governed by strain effect at low ÏB, but by charge-doping effect at high ÏB.
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Journal: Carbon - Volume 118, July 2017, Pages 343-347