RESEARCH FRONT
Covalent Functionalized Conjugated Dendrimers
165
Perkin–Elmer Lambda 705UV-vis Spectrometer. PL spectra
were carried out on Perkin–Elmer LS55 Luminescence Spec-
trometer. MALDI-TOF mass spectra were recorded on a Bruker
BIFLEX III time-of-flight (TOF) mass spectrometer (Bruker
Daltonics, Billerica, MA, USA) using a 337 nm nitrogen laser
with dithranol as matrix. Cyclic voltammetry was performed
using a BASI Epsilon workstation and measurements were
carried out in acetonitrile containing 0.1 M nBu4NPF6 as the
supporting electrolyte. Carbon electrode was used as a working
electrode and a platinum wire as a counter electrode. All
potentials were recorded versus Ag/AgCl (3 M NaCl (aq.)) as a
reference electrode. The photoluminescence efficiencies were
determined on the HORIBA JOBIN YVON Nanolog FL3–2iHR
spectrometer equipped with F3018 integration sphere.
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Device Fabrication and Characterization
OLEDs were fabricated on pre-patterned ITO with sheet
resistance 10–20 O squareꢀ1. The substrate was ultrasonically
cleaned with acetone, detergent, deionized water, and 2-propanol.
Oxygen plasma treatment was performed for 10 min as the final
step of substrate cleaning to improve the contact angle just before
film coating. Onto the ITO glass was spin-coated a layer of
PEDOT:PSS film with a thickness of 40nm from its aqueous
dispersion, aiming to improve the hole injection and to avoid
the possibility of leakage. PEDOT:PSS film was dried at 2008C
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ITO/PEDOT:PSS surface. Typical thickness of the emitting layer
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nitrogen circulation. The luminescence of the device was mea-
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luminescence was calibrated after the encapsulation of devices
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Experimental procedures and characterization data, H NMR
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Acknowledgement
This work was supported by the Major State Basic Research Development
Program (No. 2006CB921602 and 2009CB623601) from the Ministry of
Science and Technology, China, and National Natural Science Foundation
of China.
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