Abstract
Doping and stability of monolayer low defect content graphene transferred on a silicon dioxide substrate on silicon are investigated by micro-Raman spectroscopy and atomic force microscopy (AFM) during thermal treatments in oxygen and vacuum controlled atmosphere. The exposure to molecular oxygen induces graphene changes as evidenced by a blue-shift of the G and 2D Raman bands, together with the decrease of I<inf>2D</inf>/I<inf>G</inf> intensity ratio, which are consistent with a high p-type doping (∼10<sup>13</sup> cm<sup>-2</sup>) of graphene. The successive thermal treatment in vacuum does not affect the induced doping showing this latter stability. By investigating the temperature range 140-350 °C and the process time evolution, the thermal properties of this doping procedure are characterized, and an activation energy of ∼56 meV is estimated. These results are interpreted on the basis of molecular oxygen induced ∼10<sup>13</sup> cm<sup>-2</sup> p-type doping of graphene with stability energy >49 meV and postdoping reactivity in ambient atmosphere due to reaction of air molecules with oxygen trapped between graphene and substrate.
Lingua originale | English |
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pagine (da-a) | 22718-22723 |
Numero di pagine | 6 |
Rivista | JOURNAL OF PHYSICAL CHEMISTRY. C |
Volume | 119 |
Stato di pubblicazione | Published - 2015 |
All Science Journal Classification (ASJC) codes
- ???subjectarea.asjc.2500.2504???
- ???subjectarea.asjc.2100.2100???
- ???subjectarea.asjc.1600.1606???
- ???subjectarea.asjc.2500.2508???