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23% Enhanced Efficiency Of Polymer Solar Cells Processed With 1-Chloronaphthalene As The Solvent Additive Organic Electronics, Xiong Gong
Xiong Gong
No abstract provided.
Multilayer Polymer Light-Emitting Diodes: White-Light Emission With High Efficiency, Xiong Gong
Multilayer Polymer Light-Emitting Diodes: White-Light Emission With High Efficiency, Xiong Gong
Xiong Gong
This work was jointly supported by Mitsubishi Chemical Center for Advanced Materials at UC Santa Barbara, by Air Force Office of Scientific Research through the MURI Center (“Polymeric Smart Skins”, AFOSRF 49620-01-10364), Program Officer, Dr. Charles Lee. We thank Dr. Gang Yu of Dupont Displays for advice on calculating the CIE coordinates, Dr. Yoshiharu Sato at the Science & Technology Research Center of Mitsubishi Chemical Corporation in Japan for useful discussions, Dr. Steven Xiao at Organic Vision, Inc. (Canada) for providing the conjugated polymers, and Dr. Jack Ostrowski at UC Santa Barbara for synthesis of Ir-complex.
White Light Electrophosphorescence From Polyfluorene-Based Light-Emitting Diodes: Utilization Of Fluorenone Defects, Xiong Gong
Xiong Gong
Poly(9,9-dioctylfluorene-co-fluorenone) with 1% fluorenone, (PFO−F(1%)), was synthesized as a model compound to investigate the optical and electrical effects of fluorenone defects in poly(9,9-dioctylfluoren-2,7-diyl), PFO. Photoluminescence (PL) and electroluminescence (EL) measurements demonstrate that PFO−F(1%) emits stable green light. PL and EL studies indicate that Förster energy transfer to and charge carrier trapping on fluorenone defects (with subsequent fluorenone emission) are responsible for the color degradation typically observed with the polyfluorenes. By utilization of “fluorenone defects” in PFO−fluorenone copolymers (PFO−F), white electrophosphorescent light-emitting diodes were fabricated. Polymer blends were spin-cast from solution containing PFO, PFO−F (1%), and tris[2,5-bis(9,9-dihexylfluoren-2-yl)pyridine-κ2NC3]iridium(III), Ir(HFP)3. The white emission …
Preparation, Structure And Ir Spectra Of Rare Earth Complex Oxides Nanocrystallines Re~ 2sn~ 2~-~ Xb'~ Xo~ 7 (Re= Sm, Ce; B'= Fe, Co, Nix; X= 0 Asymptotically Equal To 1.0), Xiong Gong
Xiong Gong
No abstract provided.
Printable Polymer Electronics, Xiong Gong
Multilayer Led And Deposition Method, Xiong Gong
Solution Processed Infrared Polymer Photodetector, Xiong Gong
Solution Processed Infrared Polymer Photodetector, Xiong Gong
Xiong Gong
No abstract provided.
Fluids, Plasmas, And Electrical Discharges, Xiong Gong
Fluids, Plasmas, And Electrical Discharges, Xiong Gong
Xiong Gong
No abstract provided.
New Architecture For High-Efficiency Polymer Photovoltaic Cells Using Solution-Based Titanium Oxide As An Optical Spacer, Xiong Gong
Xiong Gong
Polymer photovoltaic cells with power conversion efficiencies approaching 5 % have been fabricated using titanium oxide (TiOx) as an optical spacer (see Figure). Solar cells with a TiOx layer (deposited via a sol–gel process) between the active layer and the electron-collecting aluminum electrode exhibit approximately a 50 % enhancement in short-circuit current compared to similar devices without the optical spacer, as a result of modification of the spatial distribution of the light intensity inside the device.
Polymer White Light-Emitting Diodes, Xiong Gong
Bulk Heterojunction Solar Cells With Large Open-Circuit Voltage: Electron Transfer With Small Donor-Acceptor Energy Offset, Xiong Gong
Xiong Gong
Photoinduced electron transfer is observed in polymer bulk heterojunction solar cells with very small interfacial energy offset. The results imply that open circuit voltage values close to the band gap of the semiconducting polymer should be possible for polymer bulk heterojunction solar cells just as for inorganic solar cells.
Stabilization Of Semiconducting Polymers With Silsesquioxane, Xiong Gong
Stabilization Of Semiconducting Polymers With Silsesquioxane, Xiong Gong
Xiong Gong
Polyhedral oligomeric silsesquioxanes (POSS) anchored to poly(2-methoxy-5-(2-ethylhexyloxy)-1.4-phenylenevinylene) (MEH-PPV) (MEH-PPV–POSS), and to poly(9,9-dihexylfluorenyl-2,7-diyl) (PFO) (PFO–POSS) were synthesized. Compared with the corresponding parent polymers, MEH-PPV and PFO, MEH-PPV–POSS and PFO–POSS have better thermal stability. MEH-PPV–POSS and MEH-PPV have identical absorption and photoluminescent (PL) spectra, both in solution and as thin films. They also have identical electroluminescent (EL) spectra. Devices made from MEH-PPV–POSS exhibit higher brightness (1320 cd m–2 at 3.5 V) and higher external quantum efficiency (ηext = 2.2 % photons per electron) compared to MEH-PPV (230 cd m–2 at 3.5 V and ηext = 1.5 % ph el–1). Compared with PFO …
Strain And Huckel Aromaticity: Driving Forces For A Promising New Generation Of Electron Acceptors In Organic Electronics, Xiong Gong
Xiong Gong
Straining at the leash: The main features of electron-accepting materials with a 9,9′-bifluorenylidene backbone are strain relief and a gain in aromaticity. These dimers (see picture) exhibit absorption near the red spectral region (ca. 600 nm) and HOMO (5.58–5.06 eV) and LUMO (3.37–3.09 eV) energy levels, which, together with high solubility and thermal stability render these materials attractive acceptors for bulk heterojunction (BHJ) solar cells.
Biosensors From Conjugated Polyelectrolyte Complexes, Xiong Gong
Biosensors From Conjugated Polyelectrolyte Complexes, Xiong Gong
Xiong Gong
n this paper, we report an investigation of the PL from a conjugated polyelectrolyte complex in aqueous solution. We show that the anionic conjugated polymer alone is subject to nonspecific effects on the PL (luminescence enhancement), which complicates the use of conjugated polyelectrolytes in biosensing applications. We find, however, that when a cationic polymer is added in the solution to associate with the anionic conjugated polyelectrolyte and form a charge neutral complex (CNC) [formed in aqueous solution by an anionic conjugated polyelectrolyte and a saturated cationic polyelectrolyte at a 1:1 ratio (per repeat unit)], the CNC shows little evidence of …
High Performance Polymer Light-Emitting Diodes Fabricated With A Novel Hole Injection Layer, Xiong Gong
High Performance Polymer Light-Emitting Diodes Fabricated With A Novel Hole Injection Layer, Xiong Gong
Xiong Gong
Enhanced luminance (L) and luminous efficiency (LE) of polymer light-emitting diodes (PLEDs) is demonstrated using poly (bis (tetraphenyldiamino)biphenyl-perfluorocyclobutane), poly(BTPD-Si-PFCB), as the hole injection layer. The monomer is cast directly onto the indium-tin-oxide anode and thermally polymerized in situ. Hole injection from poly(BTPD-Si-PFCB) into the Â"super yellowÂ" derivative of poly(phenylene vinylene) and into several blue emitting polymers is comparable to or better than that from poly(enthylendioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSSA). With poly(BTPD-Si-PFCB) as the hole injecting layer into super yellow, the performance is identical to that obtained with PEDOT:PSSA (LE » 8 cd/A with little fall-off even at L > 104 cd/m2). For …
Polymer Solar Cells, Xiong Gong
Polymer Solar Cells With Larger Open-Circuit Voltage, Xiong Gong
Polymer Solar Cells With Larger Open-Circuit Voltage, Xiong Gong
Xiong Gong
No abstract provided.
Solution-Processed Zinc Oxide Thin Film As A Buffer Layer For Polymer Solar Cells With An Inverted Device Structure, Xiong Gong
Xiong Gong
A solution-processed zinc oxide (ZnO) thin film as a buffer layer for polymer solar cells (PSCs) with an inverted device structure has been demonstrated. A power conversion efficiency (PCE) of 3.8% was observed from an inverted device structure with the ZnO buffer layer. Without the ZnO layer, PSCs only show a PCE of 1.67%, which is less than half the value observed from PSCs with the ZnO buffer layer. When operated at room temperature, no obvious degradation was observed from the PSCs with the ZnO layer after continuously illuminating the devices for 4 h. However, a significant degradation was observed …
Polymer Solar Cells By Novel Electron Acceptor, Xiong Gong
Polymer Solar Cells By Novel Electron Acceptor, Xiong Gong
Xiong Gong
No abstract provided.
On The Binding Of Cationic, Water-Soluble Conjugated Polymers To Dna: Electrostatic And Hydrophobic Interactions, Xiong Gong
Xiong Gong
Water-soluble, cationic conjugated polymer binds single-stranded DNA with higher affinity than it binds double-stranded or otherwise “folded” DNA. This stronger binding results from the greater hydrophobicity of single-stranded DNA. Upon reducing the strength of the hydrophobic interactions, the electrostatic attraction becomes the important interaction that regulates the binding between the water-soluble conjugated polymer and DNA. The different affinities between the cationic conjugated polymer and various forms of DNA (molecular beacons and its open state; single-stranded DNA and double-stranded DNA and single-stranded DNA and complex DNA folds) can be used to design a variety of biosensors.
Electrophosphorescence From A Conjugated Copolymer Doped With An Iridium Complex: High Brightness And Improved Operational Stability, Xiong Gong
Xiong Gong
High efficiency electrophosphorescent light-emitting diodes (LEDs), with an emission peak at 600 nm, a luminance of 2200 cd m–2, and good operational stability were fabricated from a conjugated copolymer doped with an iridium complex. The devices exhibited an external quantum efficiency of 1.5 % and a luminous efficiency of 3 cd A–1. These results demonstrate that electrophosphorescent devices with high brightness and operational stability can be produced in the form of polymer LEDs fabricated by processing the active materials from solution.
Modern Science And Technological English-Chinese Dictionary, Xiong Gong
Modern Science And Technological English-Chinese Dictionary, Xiong Gong
Xiong Gong
No abstract provided.
Temperature Dependence Of Electronic Energy Transfer From A Polymer Host To A Triplet Emitter In Light Emitting Diode Materials, Xiong Gong
Xiong Gong
We investigate the temperature dependence of electronic energy transfer between a polymer host, poly(N-vinylcarbazole) blended with 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, and the triplet emitter tris[9,9-dihexyl-2-(phenyl-4′-(pyridin-2′′-yl))fluorene] iridium(III) (Ir(DPPF)3). The photophysics of the blend are similar to those of neat poly(N-vinylcarbazole), with two emitting species corresponding to shallow and deep excimer traps. When the blend is doped with Ir(DPPF)3, the deep trap emission is preferentially quenched. This quenching cannot be explained by simple Förster energy transfer to the dopant. Instead, the data are consistent with a rapid, temperature-dependent partitioning of the energy between the two host species and the Ir(DPPF)3, each of which decays independently.
Label-Free, Dual-Analyte Electrochemical Biosensors: A New Class Of Molecular-Electronic Logic Gates, Xiong Gong
Label-Free, Dual-Analyte Electrochemical Biosensors: A New Class Of Molecular-Electronic Logic Gates, Xiong Gong
Xiong Gong
An “XOR” gate built using label-free, dual-analyte electrochemical sensors and the activation of this logic gate via changing concentrations of cocaine and the relevant cDNA as inputs are described.
High Performance Polymer Electrophosphorescent Leds, Xiong Gong
High Performance Polymer Electrophosphorescent Leds, Xiong Gong
Xiong Gong
No abstract provided.
Photocurrent And Charge Mobility In Ppv Polymers, Xiong Gong
Photocurrent And Charge Mobility In Ppv Polymers, Xiong Gong
Xiong Gong
No abstract provided.
Colorimetric Detection Of Dna, Small Molecules, Proteins, And Ions Using Unmodified Gold Nanoparticles And Conjugated Polyelectrolytes , Xiong Gong
Xiong Gong
No abstract provided.
High-Detectivity Near-Infrared Photodetectors Based On Low Band Gap Polymer Adv. Func. Mater., Xiong Gong
High-Detectivity Near-Infrared Photodetectors Based On Low Band Gap Polymer Adv. Func. Mater., Xiong Gong
Xiong Gong
No abstract provided.
Semiconducting Polymers And Polymer Optoelectronic Devices, Xiong Gong
Semiconducting Polymers And Polymer Optoelectronic Devices, Xiong Gong
Xiong Gong
No abstract provided.
Single Layer White Pleds, Xiong Gong