Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nano selective area growth of GaN by MOVPE on 4H-SiC using epitaxial
  graphene as a mask: towards integrated III-nitride / graphene / SiC
  electronics and optoelectronics
18
The categories of this paper are: econ
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
16
The categories of this paper are: stat