Статья

Adsorption of ammonia on graphene

Hugo RomeroDepartment of Physics, Pennsylvania State University, University Park, PA 16802, USAPrasoon JoshiDepartment of Electrical Engineering, Pennsylvania State University, University Park, PA 16802, USAAwnish GuptaDepartment of Physics, Pennsylvania State University, University Park, PA 16802, USAHumberto R. GutiérrezDepartment of Physics, Pennsylvania State University, University Park, PA 16802, USAMilton W. ColeMaterials Research Institute, Pennsylvania State University, University Park, PA 16802, USASrinivas TadigadapaMaterials Research Institute, Pennsylvania State University, University Park, PA 16802, USAP. C. EklundMaterials Research Institute, Pennsylvania State University, University Park, PA 16802, USA

2009en

ABI

Аннотация

We report on experimental studies of NH3 adsorption/desorption on graphene surfaces. The study employs bottom-gated graphene field effect transistors supported on Si/SiO2 substrates. Detection of NH3 occurs through the shift of the source-drain resistance maximum ('Dirac peak') with the gate voltage. The observed shift of the Dirac peak toward negative gate voltages in response to NH3 exposure is consistent with a small charge transfer (f approximately 0.068 +/- 0.004 electrons per molecule at pristine sites) from NH3 to graphene. The desorption kinetics involves a very rapid loss of NH3 from the top surface and a much slower removal from the bottom surface at the interface with the SiO2 that we identify with a Fickian diffusion process.

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Идентификаторы

DOI: 10.1088/0957-4484/20/24/245501

Цитирования и источники

Цитирований: 2Использованных источников: 0

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