Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quenching of the luminescence intensity of GaN nanowires under electron
  beam exposure: Impact of C adsorption on the exciton lifetime   Electron irradiation of GaN nanowires in a scanning electron microscope
strongly reduces their luminous efficiency as shown by cathodoluminescence
imaging and spectroscopy. We demonstrate that this luminescence quenching
originates from a combination of charge trapping at already existing surface
states and the formation of new surface states induced by the adsorption of C
on the nanowire sidewalls. The interplay of these effects leads to a complex
temporal evolution of the quenching, which strongly depends on the incident
electron dose per area. Time-resolved photoluminescence measurements on
electron-irradiated samples reveal that the carbonaceous adlayer affects both
the nonradiative and the radiative recombination dynamics.

20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
18
The categories of this paper are: econ