Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Graphene field effect transistors with Niobium contacts and asymmetric
  transfer characteristics   We fabricate back-gated field effect transistors using Niobium electrodes on
mechanically exfoliated monolayer graphene and perform electrical
characterization in the pressure range from atmospheric down to 10-4 mbar. We
study the effect of room temperature vacuum degassing and report asymmetric
transfer characteristics with a resistance plateau in the n-branch. We show
that weakly chemisorbed Nb acts as p-dopant on graphene and explain the
transistor characteristics by Nb/graphene interaction with unpinned Fermi level
at the interface.

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The categories of this paper are: math
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg