Publications

Search or filter publications

Search publications Search

Filter by type:

Filter by publication type

• Book
• Book chapter
• Conference paper
• Journal article
• Other
• Patent
• Poster
• Report
• Scholarly edition
• Software
• Thesis dissertation
• Working paper

Filter by year:

Filter from 20262025202420232022202120202019201820172016201520142013201220112010200920082007200620052004200320022001200019991998 to Filter to 20262025202420232022202120202019201820172016201520142013201220112010200920082007200620052004200320022001200019991998

---

Search results

• Journal article
  Suh M, Bailey J, Kim SW, Kim K, Yun DJ, Jung Y, Hamilton I, Chander N, Wang X, Bradley DD, Jeon DY, Kim JSet al., 2015,

  High-Efficiency Polymer LEDs with Fast Response Times Fabricated via Selection of Electron-Injecting Conjugated Polyelectrolyte Backbone Structure.

  , ACS Applied Materials & Interfaces, Vol: 7, Pages: 26566-26571, ISSN: 1944-8244

  Imidazolium ionic side-group-containing fluorene-based conjugated polyelectrolytes (CPEs) with different π-conjugated structures, poly[(9,9-bis(8'-(3″-methyl-1″-imidazolium)octyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] dibromide (F8im-Br) and poly[(9,9-bis(8'-(3″-methyl-1″-imidazolium)octyl)-2,7-fluorene)-alt-(benzo(2,1,3)thiadiazol-4,8-diyl) dibromide (F8imBT-Br), are synthesized and utilized as an electron injection layer (EIL) in green-emitting F8BT polymer light-emitting diodes (PLEDs). Both CPE EIL devices significantly outperform Ca cathode devices; 17.9 cd A(-1) (at 3.8 V) and 16.6 lm W(-1) (at 3.0 V) for F8imBT-Br devices, 11.1 cd A(-1) (at 4.2 V) and 9.1 lm W(-1) (at 3.4 V) for F8im-Br devices, and 7.2 cd A(-1) (at 3.6 V) and 7.0 lm W(-1) (at 3.0 V) for Ca devices. Importantly, unlike the F8im-Br EIL devices, F8imBT-Br PLEDs exhibit much faster electroluminescence turn-on times (<10 μs) despite both EILs possessing the same tethered imidazolium and mobile bromide ions. The F8imBT-Br devices represent, to the best of our knowledge, the highest efficiency in thin (70 nm) single-layer F8BT PLEDs in conventional device architecture with the fastest EL response time using CPE EIL with mobile ions. Our results clearly indicate the importance of an additional factor of EIL materials, specifically the conjugated backbone structure, to determine the device efficiency and response times.

  • Abstract
  • Cite
• Journal article
  Abdulla M, Renero-Lecuna C, Kim JS, Friend RHet al., 2015,

  Morphological study of F8BT:PFB thin film blends

  , ORGANIC ELECTRONICS, Vol: 23, Pages: 87-98, ISSN: 1566-1199
  • Cite
  • Citations: 11
• Journal article
  Wade J, Wood S, Beatrup D, Hurhangee M, Bronstein H, McCulloch I, Durrant JR, Kim JSet al., 2015,

  Operational electrochemical stability of thiophene-thiazole copolymers probed by resonant Raman spectroscopy.

  , Journal of Chemical Physics, Vol: 142, Pages: 244904-244904, ISSN: 1089-7690

  We report on the electrochemical stability of hole polarons in three conjugated polymers probed by resonant Raman spectroscopy. The materials considered are all isostructural to poly(3-hexyl)thiophene, where thiazole units have been included to systematically deepen the energy level of the highest occupied molecular orbital (HOMO). We demonstrate that increasing the thiazole content planarizes the main conjugated backbone of the polymer and improves the electrochemical stability in the ground state. However, these more planar thiazole containing polymers are increasingly susceptible to electrochemical degradation in the polaronic excited state. We identify the degradation mechanism, which targets the C=N bond in the thiazole units and results in disruption of the main polymer backbone conjugation. The introduction of thiazole units to deepen the HOMO energy level and increase the conjugated backbone planarity can be beneficial for the performance of certain optoelectronic devices, but the reduced electrochemical stability of the hole polaron may compromise their operational stability.

  • Abstract
  • Cite
• Journal article
  Wood S, Kim J-H, Hwang D-H, Kim J-Set al., 2015,

  Effects of Fluorination and Side Chain Branching on Molecular Conformation and Photovoltaic Performance of Donor-Acceptor Copolymers

  , CHEMISTRY OF MATERIALS, Vol: 27, Pages: 4196-4204, ISSN: 0897-4756
  • Author Web Link
  • Cite
  • Citations: 45
• Journal article
  Fei Z, Boufflet P, Wood S, Wade J, Moriarty J, Gann E, Ratcliff EL, McNeill CR, Sirringhaus H, Kim JS, Heeney Met al., 2015,

  Influence of backbone fluorination in regioregular poly(3-alkyl-4-fluoro)thiophenes

  , Journal of the American Chemical Society, Vol: 137, Pages: 6866-6879, ISSN: 1520-5126

  We report two strategies toward the synthesis of 3-alkyl-4-fluorothiophenes containing straight (hexyl and octyl) and branched (2-ethylhexyl) alkyl groups. We demonstrate that treatment of the dibrominated monomer with 1 equiv of alkyl Grignard reagent leads to the formation of a single regioisomer as a result of the pronounced directing effect of the fluorine group. Polymerization of the resulting species affords highly regioregular poly(3-alkyl-4-fluoro)thiophenes. Comparison of their properties to those of the analogous non-fluorinated polymers shows that backbone fluorination leads to an increase in the polymer ionization potential without a significant change in optical band gap. Fluorination also results in an enhanced tendency to aggregate in solution, which is ascribed to a more co-planar backbone on the basis of Raman and DFT calculations. Average charge carrier mobilities in field-effect transistors are found to increase by up to a factor of 5 for the fluorinated polymers.

  • Abstract
  • Publisher Web Link
  • Cite
• Journal article
  Higgins SG, Muir BVO, Wade J, Chen J, Striedinger B, Gold H, Stadlober B, Caironi M, Kim J-S, Steinke JHG, Campbell AJet al., 2015,

  Self-aligned megahertz organic transistors solution-processed on plastic

  , Advanced Electronic Materials, Vol: 1, ISSN: 2199-160X
  • Cite
• Journal article
  Higgins SG, Muir BVO, Wade J, Chen J, Striedinger B, Gold H, Stadlober B, Caironi M, Kim JS, Steinke JHG, Campbell AJet al., 2015,

  Organic Transistors: Self-Aligned Megahertz Organic Transistors Solution-Processed on Plastic (Adv. Electron. Mater. 5/2015)

  , Advanced Electronic Materials, Vol: 1
  • Cite
  • Citations: 1
• Journal article
  Hellmann C, Treat ND, Scaccabarozzi AD, Hollis JR, Fleischli FD, Bannock JH, de Mello J, Michels JJ, Kim J-S, Stingelin Net al., 2015,

  Solution Processing of Polymer Semiconductor: Insulator Blends-Tailored Optical Properties Through Liquid-Liquid Phase Separation Control

  , JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS, Vol: 53, Pages: 304-310, ISSN: 0887-6266
  • Cite
  • Citations: 27
• Journal article
  Perevedentsev A, Sonnefraud Y, Belton CR, Sharma S, Cass AEG, Maier SA, Kim J-S, Stavrinou PN, Bradley DDCet al., 2015,

  Dip-pen patterning of poly(9,9-dioctylfluorene) chain-conformation-based nano-photonic elements

  , Nature Communications, Vol: 6, Pages: 1-9, ISSN: 2041-1723

  Metamaterials are a promising new class of materials, in which sub-wavelength physical structures, rather than variations in chemical composition, can be used to modify the nature of their interaction with electromagnetic radiation. Here we show that a metamaterials approach, using a discrete physical geometry (conformation) of the segments of a polymer chain as the vector for a substantial refractive index change, can be used to enable visible wavelength, conjugated polymer photonic elements. In particular, we demonstrate that a novel form of dip-pen nanolithography provides an effective means to pattern the so-called β-phase conformation in poly(9,9-dioctylfluorene) thin films. This can be done on length scales ≤500 nm, as required to fabricate a variety of such elements, two of which are theoretically modelled using complex photonic dispersion calculations.

  • Abstract
  • Publisher Web Link
  • Cite
• Journal article
  Kim JS, Wood S, Shoaee S, Spencer SJ, Castro FA, Tsoi WC, Murphy CE, Sim M, Cho K, Durrant JR, Kim J-Set al., 2015,

  Morphology-performance relationships in polymer/fullerene blends probed by complementary characterisation techniques - effects of nanowire formation and subsequent thermal annealing

  , JOURNAL OF MATERIALS CHEMISTRY C, Vol: 3, Pages: 9224-9232, ISSN: 2050-7526
  • Author Web Link
  • Cite
  • Citations: 11
• Journal article
  Wood S, Wade J, Shahid M, Collado-Fregoso E, Bradley DDC, Durrant JR, Heeney M, Kim J-Set al., 2015,

  Natures of optical absorption transitions and excitation energy dependent photostability of diketopyrrolopyrrole (DPP)-based photovoltaic copolymers

  , ENERGY & ENVIRONMENTAL SCIENCE, Vol: 8, Pages: 3222-3232, ISSN: 1754-5692
  • Cite
  • Citations: 104
• Journal article
  Wade J, Steiner F, Niedzialek D, James DT, Jung Y, Yun D-J, Bradley DDC, Nelson J, Kim J-Set al., 2014,

  Charge mobility anisotropy of functionalized pentacenes in organic field effect transistors fabricated by solution processing

  , JOURNAL OF MATERIALS CHEMISTRY C, Vol: 2, Pages: 10110-10115, ISSN: 2050-7526
  • Author Web Link
  • Cite
• Journal article
  Lee S, Lee BR, Kim J-S, Song MHet al., 2014,

  Combination effect of polar solvent treatment on ZnO and polyfluorene-based polymer blends for highly efficient blue-based hybrid organic-inorganic polymer light-emitting diodes

  , JOURNAL OF MATERIALS CHEMISTRY C, Vol: 2, Pages: 8673-8677, ISSN: 2050-7526
  • Author Web Link
  • Cite
• Journal article
  Lee BR, Jung ED, Park JS, Nam YS, Min SH, Kim B-S, Lee K-M, Jeong J-R, Friend RH, Kim JS, Kim SO, Song MHet al., 2014,

  Highly efficient inverted polymer light-emitting diodes using surface modifications of ZnO layer

  , NATURE COMMUNICATIONS, Vol: 5, ISSN: 2041-1723
  • Author Web Link
  • Cite
  • Citations: 134
• Journal article
  Kim JS, Fei Z, Wood S, James DT, Sim M, Cho K, Heeney M, Kim J-Set al., 2014,

  Germanium- and Silicon-Substituted Donor–Acceptor Type Copolymers: Effect of the Bridging Heteroatom on Molecular Packing and Photovoltaic Device Performance

  , Advanced Energy Materials

  The effects of heteroatom substitution from a silicon atom to a germanium atom in donor-acceptor type low band gap copolymers, poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d]silole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl] (PSiBTBT) and poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d]germole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl] (PGeBTBT), are studied. The optoelectronic and charge transport properties of these polymers are investigated with a particular focus on their use for organic photovoltaic (OPV) devices in blends with phenyl-C70-butyric acid methyl ester (PC70BM). It is found that the longer C-Ge bond length, in comparison to C-Si, modifies the molecular conformation and leads to a more planar chain conformation in PGeBTBT than PSiBTBT. This increase in molecular planarity leads to enhanced crystallinity and an increased preference for a face-on backbone orientation, thus leading to higher charge carrier mobility in the diode configuration. These results provide important insight into the impact of the heavy atom substitution on the molecular packing and device performance of polymers based on the poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b]-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole) (PCPDTBT) backbone.

  • Abstract
  • Author Web Link
  • Cite
• Journal article
  Blakesley JC, Castro FA, Kylberg W, Dibb GFA, Arantes C, Valaski R, Cremona M, Kim JS, Kim J-Set al., 2014,

  Towards reliable charge-mobility benchmark measurements for organic semiconductors

  , ORGANIC ELECTRONICS, Vol: 15, Pages: 1263-1272, ISSN: 1566-1199
  • Author Web Link
  • Cite
  • Citations: 266
• Journal article
  Bailey J, Wright EN, Wang X, Walker AB, Bradley DDC, Kim J-Set al., 2014,

  Understanding the role of ultra-thin polymeric interlayers in improving efficiency of polymer light emitting diodes

  , JOURNAL OF APPLIED PHYSICS, Vol: 115, ISSN: 0021-8979
  • Author Web Link
  • Cite
  • Citations: 16
• Journal article
  Vaklev NL, Müller R, Muir BVO, James DT, Pretot R, van der Schaaf P, Genoe J, Kim J-S, Steinke JHG, Campbell AJet al., 2014,

  High-Performance Flexible Bottom-Gate Organic Field-Effect Transistors with Gravure Printed Thin Organic Dielectric

  , Advanced Materials Interfaces

  Gravure-printed dielectric films are presented, which are 100-nm thick, have about 1-nm root mean-square surface roughness and show high electric field strength (>300 MV/m). This dielectric is combined with an ultra-thin—less than 10 nm—layer of poly(α-methylstyrene) on top which gives state-of-the-art field-effect mobility in transistors with thermally-evaporated pentacene (0.6 cm2/Vs) and zone-cast TIPS-pentacene (0.3 cm2/Vs).

  • Abstract
  • Cite
• Journal article
  Wood S, Garnett O, Tokmoldin N, Tsoi WC, Haque SA, Kim J-Set al., 2014,

  <i>In situ</i> formation of organic-inorganic hybrid nanostructures for photovoltaic applications

  , FARADAY DISCUSSIONS, Vol: 174, Pages: 267-279, ISSN: 1359-6640
  • Cite
  • Citations: 3
• Journal article
  Razzell-Hollis J, Wade J, Tsoi WC, Soon Y, Durrant J, Kim J-Set al., 2014,

  Photochemical stability of high efficiency PTB7:PC₇₀BM solar cell blends

  , JOURNAL OF MATERIALS CHEMISTRY A, Vol: 2, Pages: 20189-20195, ISSN: 2050-7488
  • Cite
  • Citations: 142
• Journal article
  Beatrup D, Wade J, Biniek L, Bronstein H, Hurhangee M, Kim J-S, McCulloch I, Durrant JRet al., 2014,

  Polaron stability in semiconducting polymer neat films

  , CHEMICAL COMMUNICATIONS, Vol: 50, Pages: 14425-14428, ISSN: 1359-7345
  • Cite
  • Citations: 15
• Journal article
  Hodgkiss J, Conboy G, Hutchings G, Higgins S, Galbraith I, Findlay N, Taylor R, Salle M, Zhang S, Frey G, Baldea I, Samuel I, Ebenhoch B, Wudl F, Turak A, Xu B, Angioni E, Venkatramani R, Lemmer U, Perepichka D, Kanibolotsky A, Skabara P, Wildman J, Zysman-Colman E, Bradley D, McCulloch I, McDouall J, Ponomarenko S, Nelson J, Kim J-Set al., 2014,

  Organic photovoltaics and energy: general discussion

  , FARADAY DISCUSSIONS, Vol: 174, Pages: 341-355, ISSN: 1359-6640
  • Author Web Link
  • Cite
  • Citations: 1
• Journal article
  Kim J-H, Song CE, Shin N, Kang H, Wood S, Kang I-N, Kim BJ, Kim B, Kim J-S, Shin WS, Hwang D-Het al., 2013,

  High-Crystalline Medium-Band-Gap Polymers Consisting of Benzodithiophene and Benzotriazole Derivatives for Organic Photovoltaic Cells

  , ACS APPLIED MATERIALS & INTERFACES, Vol: 5, Pages: 12820-12831, ISSN: 1944-8244
  • Cite
  • Citations: 66
• Journal article
  Combe CMS, James DT, Wade J, White AJP, Kim J-S, McCulloch Iet al., 2013,

  Synthesis and morphology of asymmetric, alkyne-functionalised pentacene and 2-fluoroanthradithiophene

  , TETRAHEDRON LETTERS, Vol: 54, Pages: 6814-6818, ISSN: 0040-4039
  • Author Web Link
  • Cite
  • Citations: 3
• Journal article
  Urbina A, Park JS, Lee JM, Kim SO, Kim J-Set al., 2013,

  Work function engineering of ZnO electrodes by using p-type and n-type doped carbon nanotubes

  , NANOTECHNOLOGY, Vol: 24, ISSN: 0957-4484
  • Cite
  • Citations: 10
• Journal article
  Wood S, Franklin JB, Stavrinou PN, McLachlan MA, Kim J-Set al., 2013,

  Interfacial molecular order of conjugated polymer in P3HT:ZnO bilayer photovoltaics and its impact on device performance

  , APPLIED PHYSICS LETTERS, Vol: 103, ISSN: 0003-6951
  • Author Web Link
  • Cite
  • Citations: 12
• Journal article
  James DT, Frost JM, Wade J, Nelson J, Kim J-Set al., 2013,

  Controlling Microstructure of Pentacene Derivatives by Solution Processing: Impact of Structural Anisotropy on Optoelectronic Properties

  , ACS NANO, Vol: 7, Pages: 7983-7991, ISSN: 1936-0851
  • Author Web Link
  • Cite
  • Citations: 90
• Journal article
  Wood S, Kim JS, James DT, Tsoi WC, Murphy CE, Kim J-Set al., 2013,

  Understanding the relationship between molecular order and charge transport properties in conjugated polymer based organic blend photovoltaic devices

  , JOURNAL OF CHEMICAL PHYSICS, Vol: 139, ISSN: 0021-9606
  • Author Web Link
  • Cite
  • Citations: 25
• Journal article
  Li Z, Wong HC, Huang Z, Zhong H, Tan CH, Tsoi WC, Kim JS, Durrant JR, Cabral JTet al., 2013,

  Performance enhancement of fullerene-based solar cells by light processing

  , NATURE COMMUNICATIONS, Vol: 4, ISSN: 2041-1723
  • Author Web Link
  • Cite
  • Citations: 112
• Journal article
  Lee BR, Lee W, Thanh LN, Park JS, Kim J-S, Kim JY, Woo HY, Song MHet al., 2013,

  Highly Efficient Red-Emitting Hybrid Polymer Light-Emitting Diodes via Forster Resonance Energy Transfer Based on Homogeneous Polymer Blends with the Same Polyfluorene Backbone

  , ACS APPLIED MATERIALS & INTERFACES, Vol: 5, Pages: 5690-5695, ISSN: 1944-8244
  • Author Web Link
  • Cite
  • Citations: 40

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.