We investigate how excitonic processes in rubrene single crystals are affected by a deliberately implanted defect gradient induced by proton irradiation. Spatially resolved measurements show a gradually reduced photoluminescence quantum yield and triplet exciton diffusion length along the defect gradient. Both effects are caused by a decrease in the average triplet lifetime due to interaction with the implanted defects. The triplet lifetime was reduced by almost two orders of magnitude at the highest implanted defect density of 1017 cm–3. The strong sensitivity of the photoluminescence quantum yield to the defect density that is observed already at moderate excitation densities is caused by the combination of two effects: the dominant contribution of triplet-fusion to the observed photoluminescence and the long-range diffusion of triplet excitons.

1.
V.
Podzorov
,
V.
Pudalov
, and
M.
Gershenson
,
Appl. Phys. Lett.
82
,
1739
(
2003
).
2.
V.
Podzorov
,
E.
Menard
,
A.
Borissov
,
V.
Kiryukhin
,
J. A.
Rogers
, and
M. E.
Gershenson
,
Phys. Rev. Lett.
93
,
086602
(
2004
).
3.
V.
Podzorov
and
M.
Gershenson
,
Phys. Rev. Lett.
95
,
016602
(
2005
).
4.
V. C.
Sundar
,
J.
Zaumseil
,
V.
Podzorov
,
E.
Menard
,
R. L.
Willett
,
T.
Someya
,
M. E.
Gershenson
, and
J. A.
Rogers
,
Science
303
,
1644
(
2004
).
5.
P.
Irkhin
and
I.
Biaggio
,
Phys. Rev. Lett.
107
,
017402
(
2011
).
6.
A.
Ryasnyanskiy
and
I.
Biaggio
,
Phys. Rev. B
84
,
193203
(
2011
).
7.
I.
Biaggio
and
P.
Irkhin
,
Appl. Phys. Lett.
103
,
263301
(
2013
).
8.
S. R.
Yost
,
E.
Hontz
,
S.
Yeganeh
, and
T. V.
Voorhis
,
J. Phys. Chem. C
116
,
17369
(
2012
).
9.
J.
Lee
,
P.
Jadhav
,
P. D.
Reusswig
,
S. R.
Yost
,
N. J.
Thompson
,
D. N.
Congreve
,
E.
Hontz
,
T. V.
Voorhis
, and
M. A.
Baldo
,
Acc. Chem. Res.
46
,
1300
(
2013
).
10.
J. R.
Tritsch
,
W.-L.
Chan
,
X.
Wu
,
N. R.
Monahan
, and
X.-Y.
Zhu
,
Nat. Commun.
4
,
3679
(
2013
).
11.
P.
Irkhin
,
A.
Ryasnyanskiy
,
M.
Koehler
, and
I.
Biaggio
,
Phys. Rev. B
86
,
085143
(
2012
).
12.
O. D.
Jurchescu
,
A.
Meetsma
, and
T. T. M.
Palstra
,
Acta Crystallogr., Sect. B
62
,
330
334
(
2006
).
13.
R.
Laudise
,
C.
Kloc
,
P.
Simpkins
, and
T.
Siegrist
,
J. Cryst. Growth
187
,
449
(
1998
).
14.
J.
Ziegler
,
J.
Biersack
, and
U.
Littmark
,
The Stopping and Range of Ions in Solids
, 2nd ed. Stopping and Ranges of Ions in Matter, Vol.
1
, edited by
J.
Ziegler
(
Pergamon
,
1985
).
15.
T.
Zimmerling
,
K.
Mattenberger
,
M.
Döbeli
,
M. J.
Simon
, and
B.
Batlogg
,
Phys. Rev. B
85
,
134101
(
2012
).
16.
T.
Tombrello
,
Nucl. Instrum. Methods Phys. Res., Sect. B
24–25
,
517
(
1987
).
17.
V.
Ern
,
J.
Saint-Clair
,
M.
Schott
, and
G.
Delacote
,
Chem. Phys. Lett.
10
,
287
(
1971
).
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