Graphene has potential for applications in solar cells. We show that the short circuit current density of P3HT (Poly(3-hexylthiophene-2,5-diyl):PCBM((6,6)-Phenyl C61 butyric acid methyl ester) solar cells is enhanced by 10% upon the addition of graphene, with a 15% increase in the photon to electric conversion efficiency. We discuss the performance enhancement by studying the crystallization of P3HT, as well as the electrical transport properties. We show that graphene improves the balance between electron and hole mobilities with respect to a standard P3HT:PCBM solar cell.

1.
G.
Dennler
,
M. C.
Scharber
, and
C. J.
Brabec
, “
Polymer-fullerene bulk-heterojunction solar cells
,”
Adv. Mater.
21
(
13
),
1323
1338
(
2009
).
2.
C.
Deibel
,
V.
Dyakonov
, and
C. J.
Brabec
, “
Organic bulk-heterojunction solar cells
,”
IEEE J. Sel. Top. Quantum Electron.
16
(
6
),
1517
1527
(
2010
).
3.
C.
Deibel
,
T.
Strobel
, and
V.
Dyakonov
, “
Role of the charge transfer state in organic donor-acceptor solar cells
,”
Adv. Mater.
22
(
37
),
4097
4111
(
2010
).
4.
A. C.
Mayer
,
S. R.
Scully
,
B. E.
Hardin
,
M. W.
Rowell
, and
M. D.
McGehee
, “
Polymer-based solar cells
,”
Mater. Today
10
(
11
),
28
33
(
2007
).
6.
F.
Bonaccorso
,
Z.
Sun
,
T.
Hasan
, and
A. C.
Ferrari
, “
Graphene photonics and optoelectronics
,”
Nat. Photonics
4
(
9
),
611
622
(
2010
).
7.
I.
Hamberg
and
C. G.
Granqvist
, “
Evaporated Sn-doped {In2O3} films: Basic optical properties and applications to energy-efficient windows
,”
J. Appl. Phys.
60
(
11
),
R123
R160
(
1986
).
8.
A. E. Junge and W. O. Lytle, “
Electroconductive products and production thereof
,” U.S. patent 2566346 A (
1951
).
9.
X.
Wang
,
L.
Zhi
, and
K.
Müllen
, “
Transparent, conductive graphene electrodes for dye-sensitized solar cells
,”
Nano Lett.
8
(
1
),
323
327
(
2008
).
10.
Y.
Wang
,
X.
Chen
,
Y.
Zhong
,
F.
Zhu
, and
K. P.
Loh
, “
Large area, continuous, few-layered graphene as anodes in organic photovoltaic devices
,”
Appl. Phys. Lett.
95
(
6
),
063302
(
2009
).
11.
S.-S.
Li
,
K.-H.
Tu
,
C.-C.
Lin
,
C.-W.
Chen
, and
M.
Chhowalla
, “
Solution-processable graphene oxide as an efficient hole transport layer in polymer solar cells
,”
ACS Nano
4
(
6
),
3169
3174
(
2010
).
12.
V.
Yong
and
J. M.
Tour
, “
Theoretical efficiency of nanostructured graphene-based photovoltaics
,”
Small
6
(
2
),
313
318
(
2010
).
13.
Y.
Wang
,
D.
Kurunthu
,
G. W.
Scott
, and
C. J.
Bardeen
, “
Fluorescence quenching in conjugated polymers blended with reduced graphitic oxide
,”
J. Phys. Chem. C
114
(
9
),
4153
4159
(
2010
).
14.
N.
Yang
,
J.
Zhai
,
D.
Wang
,
Y.
Chen
, and
L.
Jiang
, “
Two-dimensional graphene bridges enhanced photoinduced charge transport in dye-sensitized solar cells
,”
ACS Nano
4
(
2
),
887
894
(
2010
).
15.
A.
Liscio
,
G. P.
Veronese
,
E.
Treossi
,
F.
Suriano
,
F.
Rossella
,
V.
Bellani
,
R.
Rizzoli
,
P.
Samorì
, and
V.
Palermo
, “
Charge transport in graphene–polythiophene blends as studied by Kelvin probe force microscopy and transistor characterization
,”
J. Mater. Chem.
21
(
9
),
2924
(
2011
).
16.
B. K.
Kuila
,
K.
Park
, and
L.
Dai
, “
Soluble P3HT-grafted carbon nanotubes: Synthesis and photovoltaic application
,”
Macromolecules
43
(
16
),
6699
6705
(
2010
).
17.
D.
Yu
,
K.
Park
,
M.
Durstock
, and
L.
Dai
, “
Fullerene-grafted graphene for efficient bulk heterojunction polymer photovoltaic devices
,”
J. Phys. Chem. Lett.
2
(
10
),
1113
1118
(
2011
).
18.
M.
Li
,
W.
Ni
,
B.
Kan
,
X.
Wan
,
L.
Zhang
,
Q.
Zhang
,
G.
Long
,
Y.
Zuo
, and
Y.
Chen
, “
Graphene quantum dots as the hole transport layer material for high-performance organic solar cells
,”
Phys. Chem. Chem. Phys.
15
(
43
),
18973
18978
(
2013
).
19.
T.
Ameri
,
P.
Khoram
,
J.
Min
, and
C. J.
Brabec
, “
Organic ternary solar cells: A review
,”
Adv. Mater.
25
(
31
),
4245
4266
(
2013
).
20.
R. A.
Street
,
D.
Davies
,
P. P.
Khlyabich
,
B.
Burkhart
, and
B. C.
Thompson
, “
Origin of the tunable open-circuit voltage in ternary blend bulk heterojunction organic solar cells
,”
J. Am. Chem. Soc.
135
(
3
),
986
989
(
2013
).
21.
A.
Gadisa
,
M.
Svensson
,
M. R.
Andersson
, and
O.
Inganäs
, “
Correlation between oxidation potential and open-circuit voltage of composite solar cells based on blends of polythiophenes/ fullerene derivative
,”
Appl. Phys. Lett.
84
(
9
),
1609
1611
(
2004
).
22.
G.
Li
,
V.
Shrotriya
,
J.
Huang
,
Y.
Yao
,
T.
Moriarty
,
K.
Emery
, and
Y.
Yang
, “
High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends
,”
Nature Mater.
4
(
11
),
864
868
(
2005
).
23.
P. W. M.
Blom
,
V. D.
Mihailetchi
,
L. J. a.
Koster
, and
D. E.
Markov
, “
Device physics of polymer:fullerene bulk heterojunction solar cells
,”
Adv. Mater.
19
(
12
),
1551
1566
(
2007
).
24.
M.
Morana
,
P.
Koers
,
C.
Waldauf
,
M.
Koppe
,
D.
Muehlbacher
,
P.
Denk
,
M.
Scharber
,
D.
Waller
, and
C.
Brabec
, “
Organic field-effect devices as tool to characterize the bipolar transport in polymer-fullerene blends: The case of {P3HT-PCBM}
,”
Adv. Funct. Mater.
17
(
16
),
3274
3283
(
2007
).
25.
A. K.
Geim
and
K. S.
Novoselov
, “
The rise of graphene
,”
Nature Mater.
6
(
3
),
183
191
(
2007
).
26.
S.
Günes
,
H.
Neugebauer
, and
N. S.
Sariciftci
, “
Conjugated polymer-based organic solar cells
,”
Chem. Rev.
107
(
4
),
1324
1338
(
2007
).
28.
Y.
Hernandez
,
V.
Nicolosi
,
M.
Lotya
,
F. M.
Blighe
,
Z.
Sun
,
S.
De
,
I. T.
McGovern
,
B.
Holland
,
M.
Byrne
,
Y. K.
Gun'Ko
,
J. J.
Boland
,
P.
Niraj
,
G.
Duesberg
,
S.
Krishnamurthy
,
R.
Goodhue
,
J.
Hutchison
,
V.
Scardaci
,
A. C.
Ferrari
, and
J. N.
Coleman
, “
High-yield production of graphene by liquid-phase exfoliation of graphite
,”
Nat. Nanotechnol.
3
(
9
),
563
568
(
2008
).
29.
F.
Bonaccorso
,
A.
Lombardo
,
T.
Hasan
,
Z.
Sun
,
L.
Colombo
, and
A. C.
Ferrari
, “
Production and processing of graphene and 2d crystals
,”
Mater. Today
15
(
12
),
564
589
(
2012
).
30.
T.
Hasan
,
F.
Torrisi
,
Z.
Sun
,
D.
Popa
,
V.
Nicolosi
,
G.
Privitera
,
F.
Bonaccorso
, and
A. C.
Ferrari
, “
Solution-phase exfoliation of graphite for ultrafast photonics
,”
Phys. Status Solidi
247
(
11–12
),
2953
2957
(
2010
).
31.
F.
Torrisi
,
T.
Hasan
,
W.
Wu
,
Z.
Sun
,
A.
Lombardo
,
T. S.
Kulmala
,
G.-W.
Hsieh
,
S.
Jung
,
F.
Bonaccorso
,
P. J.
Paul
,
D.
Chu
, and
A. C.
Ferrari
, “
Inkjet-printed graphene electronics
,”
ACS Nano
6
(
4
),
2992
3006
(
2012
).
32.
O. M.
Maragó
,
F.
Bonaccorso
,
R.
Saija
,
G.
Privitera
,
P. G.
Gucciardi
,
M. A.
Iatì
,
G.
Calogero
,
P. H.
Jones
,
F.
Borghese
,
P.
Denti
,
V.
Nicolosi
, and
A. C.
Ferrari
, “
Brownian motion of graphene
,”
ACS Nano
4
(
12
),
7515
7523
(
2010
).
33.
A. C.
Ferrari
and
J.
Robertson
, “
Origin of the 1150-cm-1 Raman mode in nanocrystalline diamond
,”
Phys. Rev. B
63
(
12
),
121405
(
2001
).
34.
A. C.
Ferrari
,
J. C.
Meyer
,
V.
Scardaci
,
C.
Casiraghi
,
M.
Lazzeri
,
F.
Mauri
,
S.
Piscanec
,
D.
Jiang
,
K. S.
Novoselov
,
S.
Roth
, and
A. K.
Geim
, “
Raman spectrum of graphene and graphene layers
,”
Phys. Rev. Lett.
97
(
18
),
187401
(
2006
).
35.
F.
Tuinstra
and
J. L.
Koenig
, “
Raman spectrum of graphite
,”
J. Chem. Phys.
53
(
3
),
1126
1130
(
1970
).
36.
C.
Casiraghi
,
A.
Hartschuh
,
E.
Lidorikis
,
H.
Qian
,
H.
Harutyunyan
,
T.
Gokus
,
K. S.
Novoselov
, and
A. C.
Ferrari
, “
Rayleigh imaging of graphene and graphene layers
,”
Nano Lett.
7
(
9
),
2711
2717
(
2007
).
37.
A. C.
Ferrari
and
J.
Robertson
, “
Interpretation of Raman spectra of disordered and amorphous carbon
,”
Phys. Rev. B
61
(
20
),
14095
14107
(
2000
).
38.
J.-C.
Bolsée
and
J.
Manca
, “
Effects of hole and electron trapping on organic field-effect transistor transfer characteristic
,”
Synth. Met.
161
(
9–10
),
789
793
(
2011
).
39.
J. S.
Kim
,
B.
Lägel
,
E.
Moons
,
N.
Johansson
,
I. D.
Baikie
,
W. R.
Salaneck
,
R. H.
Friend
, and
F.
Cacialli
, “
Kelvin probe and ultraviolet photoemission measurements of indium tin oxide work function: A comparison
,”
Synth. Met.
111–112
,
311
314
(
2000
).
40.
J. Y.
Kim
,
K.
Lee
,
N. E.
Coates
,
D.
Moses
,
T.-Q.
Nguyen
,
M.
Dante
, and
A. J.
Heeger
, “
Efficient tandem polymer solar cells fabricated by all-solution processing
,”
Science
317
(
5835
),
222
225
(
2007
).
41.
A.
Chunder
,
J.
Liu
, and
L.
Zhai
, “
Reduced graphene oxide/poly(3-hexylthiophene) supramolecular composites
,”
Macromol. Rapid Commun.
31
(
4
),
380
384
(
2010
).
42.
L.
Bu
,
E.
Pentzer
,
F. A.
Bokel
,
T.
Emrick
, and
R. C.
Hayward
, “
Growth of {polythiophene/perylene} tetracarboxydiimide {donor/acceptor} Shish-Kebab nanostructures by coupled crystal modification
,”
ACS Nano
6
(
12
),
10924
10929
(
2012
).
43.
C.
Deibel
and
V.
Dyakonov
, “
Polymer–fullerene bulk heterojunction solar cells
,”
Rep. Prog. Phys.
73
(
9
),
096401
(
2010
).
44.
M.
Lenes
,
S. W.
Shelton
,
A. B.
Sieval
,
D. F.
Kronholm
,
J. C.
(Kees) Hummelen
, and
P. W. M.
Blom
, “
Electron trapping in higher adduct fullerene-based solar cells
,”
Adv. Funct. Mater.
19
(
18
),
3002
3007
(
2009
).
45.
G. H.
Jun
,
S. H.
Jin
,
B.
Lee
,
B. H.
Kim
,
W.-S.
Chae
,
S. H.
Hong
, and
S.
Jeon
, “
Enhanced conduction and charge-selectivity by N-doped graphene flakes in the active layer of bulk-heterojunction organic solar cells
,”
Energy Environ. Sci.
6
(
10
),
3000
3006
(
2013
).
46.
K.
Maturová
,
S. S.
van Bavel
,
M. M.
Wienk
,
R. A. J.
Janssen
, and
M.
Kemerink
, “
Description of the morphology dependent charge transport and performance of polymer:fullerene bulk heterojunction solar cells
,”
Adv. Funct. Mater.
21
(
2
),
261
269
(
2011
).
47.
A.
Pivrikas
,
G.
Juska
,
T.
Osterbacka
,
M.
Westerling
,
M.
Vilionas
,
K.
Arlauskas
, and
H.
Stubb
, “
Langevin recombination and space-charge-perturbed current transients in regiorandom poly(3-hexylthiophene)
,”
Phys. Rev. B
71
(
12
),
125205
(
2005
).
48.
L. J. A.
Koster
,
M.
Kemerink
,
M. M.
Wienk
,
K.
Maturová
, and
R. A. J.
Janssen
, “
Quantifying bimolecular recombination losses in organic bulk heterojunction solar cells
,”
Adv. Mater.
23
(
14
),
1670
1674
(
2011
).
49.
K.
Vandewal
,
K.
Tvingstedt
,
A.
Gadisa
,
O.
Inganäs
, and
J. V.
Manca
, “
On the origin of the open-circuit voltage of polymer–fullerene solar cells
,”
Nature Mater.
8
(
11
),
904
909
(
2009
).
50.
K.
Vandewal
,
L.
Goris
,
I.
Haeldermans
,
M.
Nesládek
,
K.
Haenen
,
P.
Wagner
, and
J. V.
Manca
, “
Fourier-transform photocurrent spectroscopy for a fast and highly sensitive spectral characterization of organic and hybrid solar cells
,”
Thin Solid Films
516
(
20
),
7135
7138
(
2008
).
51.
A.
Maurano
,
C. G.
Shuttle
,
R.
Hamilton
,
A. M.
Ballantyne
,
J.
Nelson
,
W.
Zhang
,
M.
Heeney
, and
J. R.
Durrant
, “
Transient optoelectronic analysis of charge carrier losses in a selenophene/fullerene blend solar cell
,”
J. Phys. Chem. C
115
(
13
),
5947
5957
(
2011
).
52.
K. R.
Graham
,
P.
Erwin
,
D.
Nordlund
,
K.
Vandewal
,
R.
Li
,
G. O. Ngongang
Ndjawa
,
E. T.
Hoke
,
A.
Salleo
,
M. E.
Thompson
,
McGehee
 et al, “
Re-evaluating the role of sterics and electronic coupling in determining the open-circuit voltage of organic solar cells
,”
Adv. Mater.
25
(
42
),
6076
6082
(
2013
).
You do not currently have access to this content.