Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Coupled Optoelectronic Simulation and Optimization of Thin-Film
  Photovoltaic Solar Cells   A design tool was formulated for optimizing the efficiency of inorganic,
thin-film, photovoltaic solar cells. The solar cell can have multiple
semiconductor layers in addition to antireflection coatings, passivation
layers, and buffer layers. The solar cell is backed by a metallic grating which
is periodic along a fixed direction. The rigorous coupled-wave approach is used
to calculate the electron-hole-pair generation rate. The hybridizable
discontinuous Galerkin method is used to solve the drift-diffusion equations
that govern charge-carrier transport in the semiconductor layers. The chief
output is the solar-cell efficiency which is maximized using the differential
evolution algorithm to determine the optimal dimensions and bandgaps of the
semiconductor layers.

18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph