Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theoretical Insight into the Internal Quantum Efficiencies of
  Polymer/C$_{60}$ and Polymer/SWNT Photovoltaic Devices   The internal quantum efficiency (IQE) of an organic photovoltaic device (OPV)
is proportional to the number of free charge carriers generated and their
conductivity, per absorbed photon. However, both the IQE and the quantities
that determine it, for example, electron-hole binding, charge separation,
electron-hole recombination, and conductivity, can only be inferred indirectly
from experiments. Using density functional theory, we calculate the
excited-state formation energy, charge transfer, and zero-bias conductance in
the singlet ground state and triplet excited state across polymer/fullerene and
polymer/single walled carbon nanotube (SWNT) OPV donor/acceptor bulk
heterojunctions. Specifically, we compare polythiophene (PT) and
poly(3-methylthiophene-2,5-diyl) (P3MT) as donors and C$_{60}$ chains with
(6,4), (6,5), and (10,5) SWNTs as acceptors. We find the conductivity increases
substantially for both the excited triplet relative to the singlet ground state
and for PT compared with P3MT due to the increased charge transfer and the
resulting improvement in donor/acceptor level alignment. Similarly, the (6,4)
SWNT, with a larger SWNT band gap and greater conductivity than fullerenes,
provides the highest conductivities of 5 and 9\% of the theoretical maximum for
electron and hole carriers, respectively. This work has important implications
for both the optimization of polymer/SWNT bulk heterojunctions and the design
of new OPV bulk heterojunctions in silico.

35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
19
The categories of this paper are: eess