Novel Poly(2,3-diphenyl-1,4-phenylenevinylene) Derivatives Containing Long Branched Alkoxy and Fluorenyl Substituents:  Synthesis, Characterization, and Their Applications for Polymer Light-Emitting Diodes

Abstract

Two series of poly(2,3-diphenyl-1,4-phenylenevinylene) (DP-PPV) derivatives containing long branched alkoxy chains or fluorenyl substituents were synthesized. The branched alkoxy groups were introduced to enhance the solubility for spin-coating processes. Bulky fluorenyl groups with two hexyl chains on the 9-position were introduced to increase steric hindrance and prevent close packing of the main chain. By controlling the feed ratio of different monomers during polymerization, DP-PPV derivatives with high molecular weights were obtained. All synthesized polymers possess high glass transitions temperatures and thermal stabilities. The maximum photoluminescent emissions of the thin films are located between 498 and 564 nm. Cyclic voltammetric analysis reveals that the band gaps of these light-emitting materials are in the range from 2.4 to 2.5 eV. A double-layer electroluminescent device with the configuration of ITO/PEDOT/polymer 2/Ca/Al exhibited a low turn-on voltage (4.0 V), a very high external quantum efficiency (3.39 cd/A), and a high brightness (16 910 cd/m2).

Green emitting polyhedral oligomeric silsesquioxanes / poly(phenylene vinylene) derivative materials for highly efficient organic light emitting diodes (OLEDs)

“…The current-voltage and luminance characteristics of the diode are plotted in Figure 7. Compared to devices using the pristine polymer [17], the I-V characteristic is shifted to higher voltages, with a turn-on voltage of V to = 8 V. However, the maximum of luminance in the hybrid devices is higher, reaching 930 cd/m 2 (compared to only 303 cd/m 2 in pristine DPOC 10 -PPV based diodes). On the other hand, the maximum yield of the devices (Fig.…”

“…Tetrahydrofuran (THF) and dichloromethane (CH 2 Cl 2 ) were dried by distillation using sodium/benzophenone and calcium hydride, respectively. The synthetic routes for monomer M1 were prepared following the method previously described in the literature [17]. Figure 1 shows the structure of the monomer and the synthesis of POSS-(DPOC 10 -PPV).…”

Investigations of organic light emitting diodes with CdSe(ZnS) quantum dots

“…The size of the dots used in this work was 3.8 nm as determined from transmission electron microscopy (TEM). The co-polymer was obtained from two monomers: 1,4-bis(chloromethyl)-2-phenyl-3-(9,9-di hexylfluoren-2-yl)benzene (M1) and 1,4-bis(bromomethyl)-2-methoxy-5-(2 ethylhexoxy)benzene (M2) whose synthesis was previously described in the literature [23,24]. After preparation of a solution having the defined ratio M1/M2 in the THF, a solution of potassium tert-butoxide (tert-BuOK) in THF was added.…”

Electroluminescence from a conjugated polymer grafted with CdSe/ZnS: High brightness and improved efficiency

“…Scheme lists the synthetic route for polymers S1PPV – S3PPV . The compound (4) was synthesized as described previously in the literature 12…”