Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effects of metallic absorption and the corrugated layer on the optical
  extraction efficiency of organic light-emitting diodes   The absorption of a metallic cathode in OLEDs is analyzed by using FDTD
calculation. As the light propagates parallel to the layer, the intensity of Ez
polarization decreases rapidly. The intensity at 2.0 um from the dipole is less
than a quarter of that at 0.5 um. The strong absorption by a cathode can be a
critical factor when considering the increase of optical extraction by means of
bending the optical layers. The calculation indicates that the corrugation of
layers helps the guided light escape the guiding layer, but also increases the
absorption into a metallic cathode. The final optical output power of the
corrugated OLED can be smaller than that of the flat OLED. On the contrary, the
corrugated structure with a non-absorptive cathode increases the optical
extraction by nearly two times.

2
The categories of this paper are: math
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas