Co-reporter:Yunxia JinKaiqing Wang, Yuanrong Cheng, Qibing Pei, Yuxi Xu, Fei Xiao
ACS Applied Materials & Interfaces 2017 Volume 9(Issue 5) pp:
Publication Date(Web):January 16, 2017
DOI:10.1021/acsami.6b15025
In this work, a composite silver nanowire (AgNW) transparent electrode that is large-area ultrasmooth without conductivity or transmittance scarifice, removable but with good resistance to both water and organic solvent, is reported. Via a simple low-temperature solution process without complicated transfer steps or additional pressure pressing, a new kind of AgNWs composite with biocompatible and patternable chitosan polymer complex demonstrates a quite low root-mean-square roughness ∼7 nm at a largest reported scan size of 50 μm × 50 μm, which is among the best flat surface. After long-term exposure to both water and organic solvent, it still shows strong adhesion, unchanged transparency, and no obvious conductivity reduction, suggesting a good stability staying on the substrate. Meanwhile, the polymer and silver nanowire in the composite electrode can be damaged via the same process through concentrated acid or base etching to leave off the substrate, allowing a simple patterning technology. Besides, the imported insulating polymer does not lower down the opto-electrical performance, and a high figure of merit close to 300 is obtained for the composite electrode, significantly outperforming the optoelectronic performance of indium-tin oxide (ITO) coated plastics (∼100) and comparable to ITO-coated glass. It shows great advantage to replace ITO as a promising transparent electrode.Keywords: chitosan; sensor; Silver nanowire; stability; surface roughness; transparent composite electrode;
Co-reporter:Lingqiang Kong, Tianke Qi, Zhidong Ren, Yunxia Jin, Yan Li, Yuanrong Cheng and Fei Xiao
RSC Advances 2016 vol. 6(Issue 73) pp:68560-68567
Publication Date(Web):05 Jul 2016
DOI:10.1039/C6RA10594G
Perfluorocyclobutylidene (PFCB) polymers have gained much interest as the next generation fluoropolymers due to their low dielectric constant, low surface energy, thermal and thermal oxidative stability and chemical resistance. Herein, we obtained a low-k cross-linked polymer by incorporating the bulk rigid adamantyl, perfluorocyclobutylidene and benzocyclobutene groups into a single monomer. The k value of the obtained polymer was 2.38 and the dielectric loss was less than 0.0004 at 1 MHz due to the effect of the C–F bond and the bulk rigid adamantyl group. The polymer film also showed excellent uniformity and planarity with a surface roughness of less than 0.60 nm on a 1 × 1 μm2 area and good hydrophobicity with a water contact angle of 113.5°. Due to the highly cross-linked network structure and the introduction of the rigid adamantly group, the polymer exhibited a high Young's modulus, high hardness and good thermal stability (Td > 400 °C in nitrogen).
Co-reporter:Lingqiang Kong;Yuanrong Cheng;Yunxia Jin;Tianke Qi
Journal of Applied Polymer Science 2016 Volume 133( Issue 21) pp:
Publication Date(Web):
DOI:10.1002/app.43456
ABSTRACT
High performance epoxy resins have attracted much research interest in the last decades. Herein, two novel epoxy monomers containing cycloaliphatic hydrocarbon, 1,4-bis(4-(N,N-diglycidylamino)phenoxy)cyclohexane (CyhEP) and 1,3-bis(4-(N,N-diglycidylamino)phenoxy)adamantane (AdaEP) were synthesized and characterized. They were cured with 4-methylhexahydrophthalic anhydride (MHHPA) to prepare the highly crosslinked thermosets. Both epoxy resins show good thermal stability (Td5 > 300 °C), high glass transition temperature (> 200 °C), and high storage modulus (> 3.2 GPa) due to their highly crosslinked structure. The AdaEP/MHHPA resin shows a low dielectric constant (3.4 at 1 MHz) because of the introduction of bulky rigid adamantane into the polymer. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43456.
Co-reporter:Zhidong Ren;Yuanrong Cheng;Yan Li
Journal of Applied Polymer Science 2016 Volume 133( Issue 22) pp:
Publication Date(Web):
DOI:10.1002/app.43491
ABSTRACT
Three novel bismaleimide monomers (MBA-BMI, EBA-BMI, and PBA-BMI) with unsymmetrical backbone and different pendant groups were synthesized using asymmetric diamine and maleic anhydride as the precursors. The prepared bismaleimide monomers show good solubility in common organic solvents such as acetone and tetrahydrofuran. The EBA-BMI melt treated at 180 °C also shows low viscosity about 190–934 mPa s at the temperature range of 160–139 °C below its melting point (166 °C). In addition to the good processability, all three cured bismaleimides show high storage moduli at high temperatures (2.0 GPa at 400 °C), high glass transition temperatures over 400 °C, and good thermal stability with the 5% weight loss temperatures around 470 °C under nitrogen atmosphere. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43491.
Co-reporter:Zhidong Ren;Yuanrong Cheng;Lingqiang Kong;Tianke Qi
Journal of Applied Polymer Science 2016 Volume 133( Issue 3) pp:
Publication Date(Web):
DOI:10.1002/app.42882
ABSTRACT
A novel bismaleimide (DOPO-BMI) with unsymmetrical chemical structure and DOPO pendant group has been prepared. The particular molecular structure makes DOPO-BMI show an intrinsic amorphous state with a Tg about 135°C and excellent solubility in most organic solvents, which is beneficial to the processability of bismaleimide composite materials. A series of bismaleimide-triazine (BT) resins have been prepared based on DOPO-BMI and 2,2-bis(4-cyanatophenyl)propane at various weight ratios. The prepared BT resins show outstanding solubility in organic solvent and low viscosity about 10–671 mPa s at 180°C. The cured BT resins exhibit high glass transition temperature (Tg) over 316°C. As the weight ratio of DOPO-BMI increases to 80% (BT80), the Tg can rise to 369°C (tan δ). The cured BT resins also show good thermal stability with the 5% weight loss temperature over 400°C under both nitrogen and air atmosphere. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42882.
Co-reporter:Yunxia Jin;Lu Li;Yuanrong Cheng;Lingqiang Kong;Qibing Pei
Advanced Functional Materials 2015 Volume 25( Issue 10) pp:1581-1587
Publication Date(Web):
DOI:10.1002/adfm.201403293
Silver nanowire (AgNW) networks are a promising candidate to replace indium tin oxide (ITO) as transparent conductors. In this paper, a novel transparent composite conductor composed of AgNW/biocompatible alginate gel on a flexible polyethylene terephthalate (PET) substrate, with synchronously enhanced adhesion and reduced resistivity, is prepared without high-temperature annealing. The sheet resistance of the flexible AgNW/PET film reduces from 300 to 50.3 Ohm sq−1 at transmittance of 94%. The optical and electrical performance is superior to that obtained from the flexible ITO film on PET. Meanwhile, the sheet resistance does not show great change after tape test, suggesting a good adhesion of AgNW to the polymer substrate. Moreover, the AgNW composite film shows a good stability to resist long-term storage, solvent damage, and ultrasonication. Finally, polymer solar cells employing the composite AgNW film as the electrode are realized, displaying an efficiency of 2.44%.
Co-reporter:Lingqiang Kong, Yuanrong Cheng, Yunxia Jin, Zhidong Ren, Yan Li and Fei Xiao
Journal of Materials Chemistry A 2015 vol. 3(Issue 14) pp:3364-3370
Publication Date(Web):13 Feb 2015
DOI:10.1039/C4TC02854F
Low dielectric polymers play an important role in replacing traditional inorganic dielectric materials in advanced electronic manufacturing due to their excellent physical and chemical properties. Herein we report the preparation and characterization of two novel low-k dielectric polymers by introducing adamantane into benzocyclobutene. Because the adamantyl group has low polarizability and can increase the free volume of the polymer, both polymers showed low dielectric constants (2.5) and low dielectric loss (<0.001) at the frequency within 10 KHz–5 MHz. They also showed excellent film uniformity and planarity with the surface roughness less than 0.6 nm and good hydrophobicity with the contact angle larger than 107°. Due to the high cross-linked network structure, both of the adamantyl-based BCB polymers exhibited high glass transition temperature (>350 °C), high storage modulus and good thermal stability (Td > 400 °C in nitrogen). Especially, the p-Ada-TVS-BCB polymer showed a low coefficient of thermal expansion (41 μm m−1 °C−1). All of these good properties are in accord with the requirement of the interconnect fabrication of Cu metallization using the damascene process. Both of the polymers are suitable for the utilization in the electronic packing industry.
Co-reporter:Yunxia Jin, Dunying Deng, Yuanrong Cheng, Lingqiang Kong and Fei Xiao
Nanoscale 2014 vol. 6(Issue 9) pp:4812-4818
Publication Date(Web):21 Jan 2014
DOI:10.1039/C3NR05820D
As a promising candidate to replace the brittle and expensive transparent indium tin oxide (ITO) conductor, the use of silver nanowire (AgNW) networks still involves issues such as high-temperature post-treatments and poor substrate adhesion for industrial application. Here a room-temperature soldering and one-step solution method is developed to achieve high-performance Ag nanowire transparent conductive films (TCFs). A nonconductive binder is prepared from poly(dopamine) and alginic acid which contains abundant catechol and carboxylic acid functional groups. The drying of the binder on the Ag nanowire percolation networks induces tighter contact among the nanowires and strong adhesion to the substrate, simultaneously enhancing the electrical and mechanical properties without a high-temperature annealing process. As a result, a highly conductive and bendable AgNW film is demonstrated on a low-cost polyethylene glycol terephthalate (PET) substrate, showing an 89% optical transmittance at λ = 550 nm and a sheet resistance of 16.3 Ohm sq−1. Its optical and electrical performances are superior to those obtained from the reported indium tin oxide (ITO) films. Moreover, the AgNW film exhibits strong adhesion to the substrate, maintaining its conductivity after 100 tape tests, and it still resists the tape test even after exposure to solvent for several hours. Most importantly, the film shows good reliability during long-term 85 °C/85% RH (relative humidity) aging, which has been rarely investigated although it is a critical requirement for industrial application. The advanced and wide-ranging features of the prepared AgNW film greatly contribute to its use as a transparent electrode in multifunctional flexible electronic devices.
Co-reporter:Yunxia Jin, Yuanrong Cheng, Dunying Deng, Chengjie Jiang, Tianke Qi, Donglun Yang, and Fei Xiao
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 3) pp:1447
Publication Date(Web):December 31, 2013
DOI:10.1021/am402900u
Metal transparent conductive films (TCFs) have received increasing attention in various flexible electronics. However, there are two crucial issues that need to be addressed: (1) strong adhesion between metal TCFs and the flexible substrates and (2) high conductivity with short treatment time and low process temperature, simultaneous with high transparency. In this paper, a site-selective electroless plating combination with poly(dopamine) modification is demonstrated to fabricate a new high performance transparent conductor composed of a periodic two-dimensional silver network on a heat sensitive flexible substrate at room temperature. The TCF reveals an extremely high ratio of DC to optical conductivity (σDC/σOp) value in the range of 350–1000 for various fabricated silver grid films. It also exhibits particularly strong adhesion, which can resist ultrasonic treatment in water or organic solvent for several hours. Its reliability (stable for at least 1440 h during 85 °C/85% RH aging) meets the essential requirements for microelectronic applications. Using this method, we obtain silver grid film on a flexible polyethylene terephthalate substrate with optical transmittance of 91% and sheet resistance of 8 Ohm sq–1, which is comparable to or better than the commercially available indium tin oxide.Keywords: flexible electronics; patterning; silver grid; site-selection; surface modification;
Co-reporter:Dunying Deng, Yunxia Jin, Yuanrong Cheng, Tianke Qi, and Fei Xiao
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 9) pp:3839
Publication Date(Web):April 11, 2013
DOI:10.1021/am400480k
Conductive copper nanoinks can be used as a low-cost replacement for silver and gold nanoinks that are used in inkjet printing of conductive patterns. We describe a high-throughput, simple, and convenient method for the preparation of copper nanoparticles in aqueous solution at room temperature. Copper acetate is used as the precursor, hydrazine as the reducing agent, and short chain carboxylic acids as capping agents. The concentration of the carboxylic acid plays a key role in the preparation of such copper nanoparticles. Stable copper nanoparticles with a diameter of less than 10 nm and a narrow size distribution were prepared when high concentrations of lactic acid, citric acid, or alanine were used. Thermogravimetric analysis results showed that any lactic acid or glycolic acid adsorbed on the surface of the copper nanoparticles can be removed at a relatively low temperature, especially, glycolic acid, which can be removed from the surface at about 125 °C. Highly conductive copper films prepared using lactic acid and glycolic acid as capping agents were obtained by drop coating a copper nanoparticle paste onto a glass slide followed by low temperature sintering. The electrical resistivity of the copper film using glycolic acid as the capping agent was 25.5 ± 8.0 and 34.8 ± 9.0 μΩ·cm after annealing at 150 and 200 °C for 60 min under nitrogen, respectively. When lactic acid was used as the capping agent, the electrical resistivity of the copper films was 21.0 ± 7.0 and 9.1 ± 2.0 μΩ·cm after annealing at 150 and 200 °C for 60 min under nitrogen, respectively, with the latter being about five times greater than the resistivity of bulk copper (1.7 μΩ·cm).Keywords: copper nanoparticles; electrical resistivity; printed electronics; short chain carboxylic acids; sintering temperature;
Co-reporter:Jun Yang, Yuanrong Cheng, Yunxia Jin, Dunying Deng, Fei Xiao
European Polymer Journal 2013 Volume 49(Issue 6) pp:1642-1653
Publication Date(Web):June 2013
DOI:10.1016/j.eurpolymj.2013.02.017
Three kinds of benzocyclobutene (BCB)-terminated imide monomers have been synthesized by the imidization and Heck reaction. The obtained BCB monomers exhibit good solubility in a wide range of organic solvents at room temperature. The BCB monomers show an exothermal curing behavior in the range of 220–270 °C. The curing kinetic parameters, the apparent activation energy (Ea), the frequency factor (A) and the reaction order (n), are obtained by non-isothermal DSC method. The cured BCB resins exhibit good thermal stability (Td5 > 435 °C), high glass transition temperature (Tg > 300 °C) and low dielectric constant. Moreover, high quality negative patterns of the BCB films are obtained after the photolithography.Graphical abstractHighlights► A series of benzocyclobutene (BCB)-terminated imide monomers were synthesized. ► Negative patterns of the BCB films were obtained after the photolithography. ► The effect of chemical structure on properties of the BCB resins was discussed.
Co-reporter:Jun Yang;Yuanrong Cheng;Yunxia Jin
Polymer International 2013 Volume 62( Issue 12) pp:1684-1691
Publication Date(Web):
DOI:10.1002/pi.4467
Abstract
Two kinds of novel benzocyclobutene (BCB) functionalized monomers were synthesized through imidization of siloxane-containing dianhydride with 4-aminobenzocyclobutene. The BCB monomers obtained exhibited good solubility in various organic solvents. They were converted into crosslinked polymer via ring opening and the following Diels–Alder reaction at proper temperature. The curing kinetics were studied by non-isothermal differential scanning calorimetry. The BCB polymers showed good thermal stability, excellent dielectric properties, low water absorption and good planarization. Moreover, the thermal and mechanical properties of the BCB resins could be adjusted by the length of the siloxane unit. The BCB resins with a shorter siloxane chain exhibited higher glass transition temperature, higher modulus and lower coefficient of thermal expansion than BCB resins with longer chains. © 2013 Society of Chemical Industry
Co-reporter:Yuanrong Cheng, Tianke Qi, Yunxia Jin, Dunying Deng, Fei Xiao
Polymer 2013 Volume 54(Issue 1) pp:143-147
Publication Date(Web):8 January 2013
DOI:10.1016/j.polymer.2012.11.008
Maleimidobenzoxazine monomer functionalized with benzocyclobutene (BCB) and its cured resin has been successfully prepared. BCB-modified maleimidobenzoxazine monomer (HMI–AB) was synthesized by the reaction of 4-aminobenzocyclobutene (AMBCB), p-hydroxyphenylmaleimide (HMI) and paraformaldehyde in dioxane under reflux. Fourier transform infrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance spectroscopy (NMR) were used to characterize the structure of the monomer. The monomer HMI–AB possesses three kinds of polymerizable functional groups of BCB, maleimide and benzoxazine. The polymerization behavior of the monomer is studied by differential scanning calorimetry (DSC) and FTIR. DMA study demonstrates that the cured resin show high storage modulus and high Tg at ca. 350 °C. TGA study shows that the cured resin possess good thermal stability.
Co-reporter:Dunying Deng, Yuanrong Cheng, Yunxia Jin, Tianke Qi and Fei Xiao
Journal of Materials Chemistry A 2012 vol. 22(Issue 45) pp:23989-23995
Publication Date(Web):26 Sep 2012
DOI:10.1039/C2JM35041F
Copper nanoparticles are an alternative for the currently used silver and gold nanoparticles in inkjet printing of conductive patterns because of the low cost and high electrical conductivity. However, a serious impediment to using copper nanoparticles for conductive inks is their spontaneous oxidation. This paper describes a simple, large-scale and high-throughput (0.2 M) process for the synthesis of copper nanoparticles in aqueous solution at room temperature in a short reaction period. The well-dispersed antioxidative copper pastes were prepared by dispersing the nanoparticles in an ethanol solution of lactic acid, and then depositing on glass slides. The resistivity of the conductive copper film was 14.0 ± 4.5 μΩ cm after annealing at 200 °C for 30 min in nitrogen, which was about eight times of the resistivity of bulk copper (1.7 μΩ cm). The copper nanoparticles and films were characterized by TEM, UV-vis, SEM, XRD and XPS. Lactic acid-stabilized copper nanoparticles showed relatively better disperse stability and resistance to oxidation than the other carboxylic acids. Furthermore, the copper film after annealing at 200 °C for 30 min in nitrogen showed antioxidative characteristics. It was experimentally proven that lactic acid could react with the copper oxides surrounding copper nanoparticles to form copper lactate, which was then reduced to copper in the annealing process.
Co-reporter:Jun Yang, Yuanrong Cheng, Fei Xiao
European Polymer Journal 2012 Volume 48(Issue 4) pp:751-760
Publication Date(Web):April 2012
DOI:10.1016/j.eurpolymj.2012.01.006
A series of benzocyclobutene-functionalized siloxane thermosets were prepared to investigate the relationship between the monomer’s chemical structure and the properties of the corresponding polymer. Monomer 1,1,3,3-tetramethyl-1,3-bis[2′-(4′-benzocyclobutenyl)]vinyldisiloxane (DVS-BCB) and 1,3,5,7-tetramethyl-1,3,5,7-tetra[2′-(4′-benzocyclobutenyl)]vinylcyclotetrasiloxane (CYC-BCB) were synthesized by Heck reaction. Copolymer Poly(DVS-BCB-co-POSS) was obtained through incorporating octavinyl-T8-silsesquioxane (Vinyl-POSS) into DVS-BCB matrix via Diels–Alder reaction. The oligomers, P-DVS-BCB, P-CYC-BCB and P-Poly(DVS-BCB-co-POSS), were obtained by refluxing the mesitylene solution of the BCB monomers at the BCB ring opening temperature. The BCB monomers and oligomers showed a similar curing behavior with an exothermic peak temperature near 260 °C. The curing kinetic parameters, the apparent activation energy (Ea), the frequency factor (A) and the reaction order (n), were obtained by non-isothermal DSC method. The BCB polymers possessed good thermal stability (Td > 450 °C in N2). Due to the highly crosslinked network structure, CYC-BCB polymer exhibited higher glass transition temperature, higher modulus and lower coefficient of thermal expansion than DVS-BCB and Poly(DVS-BCB-co-POSS) polymers. Moreover, the BCB polymers also demonstrated low dielectric constants (<2.8 at 1 MHz) and low water absorptions. The films prepared from the BCB oligomer solution showed a well planarization (root-mean-square roughness <0.5 nm).Graphical abstractHighlights► A series of benzocyclobutene-functionalized siloxane thermosets were prepared. ► The resin with cyclic structure showed improved thermal mechanical properties. ► The effect of chemical structure on properties of the polymer was investigated.
Co-reporter:Yuanrong Cheng, Jun Yang, Yunxia Jin, Dunying Deng, and Fei Xiao
Macromolecules 2012 Volume 45(Issue 10) pp:4085-4091
Publication Date(Web):May 2, 2012
DOI:10.1021/ma3004218
Benzocyclobutene- (BCB-) functionalized benzoxazine (BOZ) monomers and resins have been successfully prepared. BCB-functionalized BOZ monomers were synthesized by the reaction of 4-aminobenzocyclobutene (AMBCB), phenol and paraformaldehyde or by the reaction of 4-hydroxylbenzocyclobutene (OHBCB), arylamine, and paraformaldehyde in toluene under reflux. Fourier transform infrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance spectroscopy (NMR) are used to characterize the structure of the monomers. The monomers possess two kinds of ring-opening polymerizable functional groups of BCB and BOZ. So the monomers can be cured at proper temperature to prepare highly cross-linked resins. The polymerization behavior of the monomers is studied by differential scanning calorimetry (DSC) and FTIR. DMA study demonstrates that these polymers show high storage moduli which can be maintained in a wide temperature range up to 300 °C and high Tg at ca. 350 °C. The TGA study shows that the cured resins possess good thermal stability.
Co-reporter:Haowei Yang, Yuanrong Cheng, Fei Xiao
Applied Surface Science 2011 Volume 258(Issue 4) pp:1572-1580
Publication Date(Web):1 December 2011
DOI:10.1016/j.apsusc.2011.09.137
Abstract
The superhydrophobic polyphenylsilsesquioxane (PPSQ)/nanosilica composite coatings were prepared by spray coating method with nano fumed silica (NFS) particles embedded in PPSQ matrix. The water contact angle (WCA) increased from 92.9° to 152.5° and the sliding angle (SA) decreased from more than 60° to 3.9° as the NFS content increased. The superhydrophobicity retained up to 500 °C, sustained by the hierarchical micro–nano structures and excellent thermal stability of PPSQ. A superhydrophobic PPSQ coating with WCA of 152.6° and SA of 7.8° was obtained by solvent–nonsolvent method for comparison as well. However, it gradually lost superhydrophobicity at 200 °C because of the elimination of nanostructures by the thermal softening of PPSQ.
Co-reporter:Hui-ying Fu, Xin-dong Gao, Gao-yu Zhong, Zhi-yang Zhong, Fei Xiao, Bing-xian Shao
Journal of Luminescence 2009 Volume 129(Issue 10) pp:1207-1214
Publication Date(Web):October 2009
DOI:10.1016/j.jlumin.2009.06.004
Benzothiazole-based blue fluorescent materials N-(4-(benzo[d]thiazol-2-yl)phenyl)-N-phenylbenzenamine (BPPA) and N-(4-(benzo[d]thiazol-2-yl)phenyl)-N-phenylnaphthalen-1-amine (BPNA) were synthesized for use in organic light-emitting diodes (OLEDs). Electroluminescent device with a configuration of ITO/NPB/BPPA/BCP/Alq3/LiF/Al showed a maximum brightness of 3760 cd/m2 at 14.4 V with the CIE coordinates of (0.16, 0.16). A current efficiency of 3.01 cd/A and an external quantum efficiency of 2.37% at 20 mA/cm2 were obtained from this device. Molecules derived from BPPA and BPNA with incorporated dicyanomethylidene, which is a functional group for most red fluorescent molecules, were designed, synthesized and characterized to study the red fluorescence properties of the benzothiazole derivatives.
Co-reporter:Hui-Ying Fu, Xiao-Yu Sun, Xin-dong Gao, Fei Xiao, Bing-Xian Shao
Synthetic Metals 2009 Volume 159(3–4) pp:254-259
Publication Date(Web):February 2009
DOI:10.1016/j.synthmet.2008.09.013
Two benzothiazole derivatives, 4-(benzo[d]thiazol-2-yl)-N-(4-(benzo[d]thiazol-2-yl)phenyl)-N-phenylbenzenamine (BBPA) and 4-(benzo[d]thiazol-2-yl)-N-(4-(benzo[d]thiazol-2-yl)phenyl)-N-naphthylbenzenamine (BBNA), were synthesized and characterized. Electroluminescent devices with compound BBPA or BBNA as the blue-emitting layer were fabricated. The triple-layer device, in which BBPA acted as the blue-emitter, NPB as the hole-transporting layer and TPBI as the electron-transporting layer (Device 1), showed a current efficiency of 5.24 cd/A, a power efficiency of 1.21 lm/W and an external quantum efficiency of 2.88% at a driving current density of 20 mA/cm2. The double-layer device with BBNA as the emitting layer and electron-transporting layer and NPB as the hole-transporting layer (Device 4) exhibited a maximum brightness of 1430 cd/m2 at 13 V with the CIE coordinates (0.21, 0.23).
Co-reporter:Hui-Ying Fu;Qun-Liang Song;Xiao-Yu Sun;Xiao-Yuan Hou;Bing-Xian Shao
Chinese Journal of Chemistry 2007 Volume 25(Issue 9) pp:1242-1245
Publication Date(Web):17 SEP 2007
DOI:10.1002/cjoc.200790231
Organic photovoltaic (OPV) cells were fabricated via vacuum vapor deposition with {4-[2-(3-dicyanomethylidene-5,5-dimethylcyclohexenyl)vinyl]phenyl}di(1-naphthyl)amine (DNP-2CN) as the electron donor, and fullerene (C60) as the electron acceptor. A thin film (10 nm) of tris(8-quinolinolato)aluminum (Alq3) was adopted as the buffer layer. A device based on this DNP-2CN exhibited an open circuit voltage (Voc) of 370 mV, a short-circuit current density (Jsc) of 0.61 mA·cm−2, and a white-light power conversion efficiency (() of 0.09% (AM1.5, 75 mW·cm−2).
Co-reporter:Hui-ying Fu, Huan-rong Wu, Xiao-yuan Hou, Fei Xiao, Bing-xian Shao
Synthetic Metals 2006 Volume 156(11–13) pp:809-814
Publication Date(Web):1 June 2006
DOI:10.1016/j.synthmet.2006.04.013
Two N-aryl carbazole derivatives: 3-2-(3,3-dicyanomethylene-5,5-dimethyl-1-cyclohexylidene)vinyl-N-naphthyl-carbazole (NCz-2CN) and 3,6-bis(2-(3,3-dicyanomethylene-5,5-dimethyl-1-cyclohexylidene)vinyl-N-phenyl-carbazole (PCz-4CN), with the molecular structure of donor-π-acceptor, have been synthesized and characterized. They are red emitters in the solid films with a peak wavelength at 630 nm of NCz-2CN and 666 nm of PCz-4CN. Non-doped orange-red electroluminescent devices with the structure of ITO/NPB/NCz-2CN/BCP/Alq3/LiF/Al were fabricated. The device showed orange-red emission at λmax = 628 nm and a maximum luminance of 4110 cd/m2 obtained at 15 V. The maximum luminous efficiency was 0.49 lm/W and the current efficiency was 2.09 cd/A.
Co-reporter:Huiying Fu, Yiqiang Zhan, Jixiang Xu, Xiaoyuan Hou, Fei Xiao
Optical Materials 2006 Volume 29(2–3) pp:348-354
Publication Date(Web):November 2006
DOI:10.1016/j.optmat.2005.09.074
A novel family of red fluorescent materials for organic light emitting diodes (OLEDs), 4-(2-(3,3-dicyanomethylene-5,5-dimethyl-1-cyclohexylidene)vinyl) phenyldi(1-naphthyl)amine (DNP-2CN), 4-(2-(3,3-dicyanomethylene-5,5-dimethyl-1-cyclohexylidene)vinyl)phenyl(1-naphthyl)phenylamine (DPN-2CN), bis(4-(2-(3,3-dicyanomethylene-5,5-dimethyl-1-cyclohexylidene)vinyl)phenyl)(1-naphthyl)amine (DPN-4CN), were synthesized and characterized. These materials show red photoluminescence with a peak wavelength at 660–706 nm in the solid films. Two kinds of electroluminescent (EL) devices were fabricated: dye-doped OLED with a structure of ITO/NPB/red dopant (3 wt%): Alq3/PBD/LiF/Al and undoped OLED with a structure of ITO/NPB/red emitter/PBD/LiF/Al, where DNP-2CN and DPN-2CN were used as dopants and emitters. Both EL devices exhibit bright red emission centered at 640–670 nm.
Co-reporter:Lingqiang Kong, Yuanrong Cheng, Yunxia Jin, Zhidong Ren, Yan Li and Fei Xiao
Journal of Materials Chemistry A 2015 - vol. 3(Issue 14) pp:NaN3370-3370
Publication Date(Web):2015/02/13
DOI:10.1039/C4TC02854F
Low dielectric polymers play an important role in replacing traditional inorganic dielectric materials in advanced electronic manufacturing due to their excellent physical and chemical properties. Herein we report the preparation and characterization of two novel low-k dielectric polymers by introducing adamantane into benzocyclobutene. Because the adamantyl group has low polarizability and can increase the free volume of the polymer, both polymers showed low dielectric constants (2.5) and low dielectric loss (<0.001) at the frequency within 10 KHz–5 MHz. They also showed excellent film uniformity and planarity with the surface roughness less than 0.6 nm and good hydrophobicity with the contact angle larger than 107°. Due to the high cross-linked network structure, both of the adamantyl-based BCB polymers exhibited high glass transition temperature (>350 °C), high storage modulus and good thermal stability (Td > 400 °C in nitrogen). Especially, the p-Ada-TVS-BCB polymer showed a low coefficient of thermal expansion (41 μm m−1 °C−1). All of these good properties are in accord with the requirement of the interconnect fabrication of Cu metallization using the damascene process. Both of the polymers are suitable for the utilization in the electronic packing industry.
Co-reporter:Dunying Deng, Yuanrong Cheng, Yunxia Jin, Tianke Qi and Fei Xiao
Journal of Materials Chemistry A 2012 - vol. 22(Issue 45) pp:NaN23995-23995
Publication Date(Web):2012/09/26
DOI:10.1039/C2JM35041F
Copper nanoparticles are an alternative for the currently used silver and gold nanoparticles in inkjet printing of conductive patterns because of the low cost and high electrical conductivity. However, a serious impediment to using copper nanoparticles for conductive inks is their spontaneous oxidation. This paper describes a simple, large-scale and high-throughput (0.2 M) process for the synthesis of copper nanoparticles in aqueous solution at room temperature in a short reaction period. The well-dispersed antioxidative copper pastes were prepared by dispersing the nanoparticles in an ethanol solution of lactic acid, and then depositing on glass slides. The resistivity of the conductive copper film was 14.0 ± 4.5 μΩ cm after annealing at 200 °C for 30 min in nitrogen, which was about eight times of the resistivity of bulk copper (1.7 μΩ cm). The copper nanoparticles and films were characterized by TEM, UV-vis, SEM, XRD and XPS. Lactic acid-stabilized copper nanoparticles showed relatively better disperse stability and resistance to oxidation than the other carboxylic acids. Furthermore, the copper film after annealing at 200 °C for 30 min in nitrogen showed antioxidative characteristics. It was experimentally proven that lactic acid could react with the copper oxides surrounding copper nanoparticles to form copper lactate, which was then reduced to copper in the annealing process.
![BENZENAMINE, 4,4'-[TRICYCLO[3.3.1.13,7]DECANE-1,3-DIYLBIS(OXY)]BIS-](http://img.cochemist.com/ccimg/854100/854063-95-9.png)
![BENZENAMINE, 4,4'-[TRICYCLO[3.3.1.13,7]DECANE-1,3-DIYLBIS(OXY)]BIS-](http://img.cochemist.com/ccimg/854100/854063-95-9_b.png)
![TRICYCLO[3.3.1.13,7]DECANE, 1,3-BIS(4-NITROPHENOXY)-](http://img.cochemist.com/ccimg/854100/854063-93-7.png)
![TRICYCLO[3.3.1.13,7]DECANE, 1,3-BIS(4-NITROPHENOXY)-](http://img.cochemist.com/ccimg/854100/854063-93-7_b.png)
![Copper, bis[2-(hydroxy-kO)propanoato-kO]-](http://img.cochemist.com/ccimg/16100/16039-52-4.png)
![Copper, bis[2-(hydroxy-kO)propanoato-kO]-](http://img.cochemist.com/ccimg/16100/16039-52-4_b.png)
![Phenol, 4-[1-(4-aminophenyl)-1-methylethyl]-](http://img.cochemist.com/ccimg/900/837-11-6.png)
![Phenol, 4-[1-(4-aminophenyl)-1-methylethyl]-](http://img.cochemist.com/ccimg/900/837-11-6_b.png)
