ISSN 1063-7826, Semiconductors, 2011, Vol. 45, No. 10, pp. 1339–1345. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © V.M. Svetlichnyi, E.L. Aleksandrova, L.A. Myagkova, N.V. Matyushina, T.N. Nekrasova, R.Yu. Smyslov, A.R. Tameev, S.N. Stepanenko, A.V. Vannikov,
V.V. Kudryavtsev, 2011, published in Fizika i Tekhnika Poluprovodnikov, 2011, Vol. 45, No. 10, pp. 1392–1398.
1339
1. INTRODUCTION
Multifunctional ambipolar materials (i.e., capable
of bipolar charge transport) with high luminescence
quantum yield are of particular interest for developing
organic light-emitting diodes [1–3]. For such diodes a
promising class of multifunctional materials is poly-
mers the monomeric unit of which is a donor–accep-
tor (DA) complex. In such molecules one structural
part promotes hole injection and transport; another
promotes electron injection and transport. Among
such polymers with DA properties are polyphe-
nylquinolines containing a donor heterocyclic nitro-
gen-containing fragment and an acceptor arylene rad-
ical in the repeating unit. The use of various combina-
tions of donor and acceptor structures in the
intramolecular charge-transfer complex (ICTC) or
the DA complex of the polyphenylquinoline unit
makes it possible to expand the set of systems exhibit-
ing “white” luminescence in the entire visible spectral
region, which seems necessary in developing next-
generation light-emitting devices. Synthesis of
polyphenylquinolines with nitrogen-containing het-
erocyclic substituents with good hole transport ability,
similar to indolocarbazole [4–7], can widen not only
the class of polymers for light-emitting diodes, but also
a number of materials, i.e., p-type semiconductors, for
organic field-effect transistors and photovoltaic cells.
The objective of this research is to study the photo-
physical and electrical properties of new synthesized
2,6-polyphenylquinolines containing an oxygen or
phenylamine bridging group between quinoline
cycles and alkylated derivatives of carbazole or
indolo[3,2-b]carbazole as an arylene radical.
2. TECHNIQUES AND OBJECTS
OF THE STUDY
The study was performed for polyphenylquinolines
(PPQs) of the general formula
,
which contain an oxygen (–O–) or phenylamine
(>N–Ph) bridging group (X) between quinoline
cycles; the aromatic radical (AR) contains fragments
N
X
N AR
n
AMORPHOUS, VITREOUS, AND ORGANIC
SEMICONDUCTORS
Photophysical and Electrical Properties of Polyphenylquinolines
Containing Carbazole or indolo[3,2-b]Carbazole Fragments
as New Optoelectronic Materials
V. M. Svetlichnyi
a
^, E. L. Aleksandrova
b
, L. A. Myagkova
a
, N. V. Matyushina
a
, T. N. Nekrasova
a
,
R. Yu. Smyslov
a
, A. R. Tameev
c
, S. N. Stepanenko
a
, A. V. Vannikov
c
, and V. V. Kudryavtsev
a
a
Institute of Macromolecular Compounds, Russian Academy of Science, Bolshoi pr. 31, St. Petersburg, 199004 Russia
^e-mail: valsvet@hq.macro.ru
b
Ioffe Physical Technical Institute, Russian Academy of Sciences, ul. Politekhnicheskaya 26, St. Petersburg, 194021 Russia
c
Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences,
Leninskii pr. 31, korp. 4, Moscow, 119991 Russia
Submitted March 17, 2011; accepted for publication March 28, 2011
Abstract—Photophysical and electrical properties of new synthesized 2,6-polyphenylquinolines (PPQs)
containing an oxygen or phenylamine bridging group between quinoline cycles and, as an arylene radical,
alkylated derivatives of carbazole or indolo[3,2-b]carbazole are studied. It is shown that the photosensitivity
for new PPQs is 10
4
–10
5
cm
2
/J and the photogeneration quantum yield of free carriers is as high as 0.15. Pho-
tophysical parameters increase with the phenylamine bridging group in place of the oxygen one and when
using indolocarbazole instead of carbazole. It is found that a film of polyphenylquinoline containing an oxy-
gen bridging group and an alkylcarbazole fragment in the polymer repeat unit exhibits “white” luminescence.
Both electron and hole transport with a mobility of ~10
–6
cm
2
/(V s) are detected in films of all studied poly-
mers. The conductivity value and type can be controlled by varying the chemical structure of the (oxygen or
phenylamine) bridging group between PPQ cycles and by choosing carbazole or indolo[3,2-b]carbazole
derivatives as an arylene radical.
DOI: 10.1134/S1063782611100204