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Wang, Jia
Publications (10 of 11) Show all publications
Tang, S., Murto, P., Wang, J., Larsen, C., Andersson, M. R., Wang, E. & Edman, L. (2019). On the Design of Host-Guest Light-Emitting Electrochemical Cells: Should the Guest be Physically Blended or Chemically Incorporated into the Host for Efficient Emission?. Advanced Optical Materials, 7(18), Article ID 1900451.
Open this publication in new window or tab >>On the Design of Host-Guest Light-Emitting Electrochemical Cells: Should the Guest be Physically Blended or Chemically Incorporated into the Host for Efficient Emission?
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2019 (English)In: Advanced Optical Materials, ISSN 2162-7568, E-ISSN 2195-1071, Vol. 7, no 18, article id 1900451Article in journal (Refereed) Published
Abstract [en]

It has recently been demonstrated that light‐emitting electrochemical cells (LECs) can be designed to deliver strong emission with high efficiency when the charge transport is effectuated by a majority host and the emission is executed by a minority guest. A relevant question is then: should the guest be physically blended with or chemically incorporated into the host? A systematic study is presented that establishes that for near‐infrared‐(NIR‐) emitting LECs based on poly(indacenodithieno[3,2‐b]thiophene) (PIDTT) as the host and 4,7‐bis(4,4‐bis(2‐ethylhexyl)‐4H‐silolo[3,2‐b:4,5‐b′]dithiophen‐2‐yl)benzo[c][1,2,5]‐thiadiazole (SBS) as the guest the chemical‐incorporation approach is preferable. The host‐to‐guest energy transfer in LEC devices is highly efficient at a low guest concentration of 0.5%, whereas guest aggregation and ion redistribution during device operation severly inhibits this transfer in the physical‐blend devices. The chemical‐incorporation approach also results in a redshifted emission with a somewhat lowered photoluminescence quantum yield, but the LEC performance is nevertheless very good. Specifically, an NIR‐LEC device comprising a guest‐dilute (0.5 molar%) PIDTT‐SBS copolymer delivers highly stabile operation at a high radiance of 263 µW cm−2 (peak wavelength = 725 nm) and with an external quantum efficiency of 0.214%, which is close to the theoretical limit for this particular emitter and device geometry.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
host-guest copolymers, intramolecular energy transfer, light-emitting electrochemical cells, near-infrared emission
National Category
Materials Engineering Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-164065 (URN)10.1002/adom.201900451 (DOI)000487087400020 ()
Available from: 2019-10-15 Created: 2019-10-15 Last updated: 2019-10-15Bibliographically approved
Tang, S., Murto, P., Wang, J., Larsen, C., Andersson, M. R., Wang, E. & Edman, L. (2019). On the Design of Host-Guest Light-Emitting Electrochemical Cells: Should the Guest be Physically Blended or Chemically Incorporated into the Host for Efficient Emission?. Advanced Optical Materials, 7(18), Article ID 1900451.
Open this publication in new window or tab >>On the Design of Host-Guest Light-Emitting Electrochemical Cells: Should the Guest be Physically Blended or Chemically Incorporated into the Host for Efficient Emission?
Show others...
2019 (English)In: Advanced Optical Materials, ISSN 2162-7568, E-ISSN 2195-1071, Vol. 7, no 18, article id 1900451Article in journal (Refereed) Published
Abstract [en]

It has recently been demonstrated that light-emitting electrochemical cells (LECs) can be designed to deliver strong emission with high efficiency when the charge transport is effectuated by a majority host and the emission is executed by a minority guest. A relevant question is then: should the guest be physically blended with or chemically incorporated into the host? A systematic study is presented that establishes that for near-infrared-(NIR-) emitting LECs based on poly(indacenodithieno[3,2-b]thiophene) (PIDTT) as the host and 4,7-bis(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b ']dithiophen-2-yl)benzo[c][1,2,5]-thiadiazole (SBS) as the guest the chemical-incorporation approach is preferable. The host-to-guest energy transfer in LEC devices is highly efficient at a low guest concentration of 0.5%, whereas guest aggregation and ion redistribution during device operation severly inhibits this transfer in the physical-blend devices. The chemical-incorporation approach also results in a redshifted emission with a somewhat lowered photoluminescence quantum yield, but the LEC performance is nevertheless very good. Specifically, an NIR-LEC device comprising a guest-dilute (0.5 molar%) PIDTT-SBS copolymer delivers highly stabile operation at a high radiance of 263 mu W cm(-2) (peak wavelength = 725 nm) and with an external quantum efficiency of 0.214%, which is close to the theoretical limit for this particular emitter and device geometry.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2019
Keywords
host-guest copolymers, intramolecular energy transfer, light-emitting electrochemical cells, near- infrared emission
National Category
Atom and Molecular Physics and Optics Polymer Chemistry
Identifiers
urn:nbn:se:umu:diva-164143 (URN)10.1002/adom.201900451 (DOI)000487087400020 ()
Available from: 2019-10-17 Created: 2019-10-17 Last updated: 2019-10-17Bibliographically approved
Mone, M., Tang, S., Murto, P., Abdulahi, B. A., Larsen, C., Wang, J., . . . Wang, E. (2019). Star-Shaped Diketopyrrolopyrrole-Zinc Porphyrin that Delivers 900 nm Emission in Light-Emitting Electrochemical Cells. Chemistry of Materials, 31(23), 9721-9728
Open this publication in new window or tab >>Star-Shaped Diketopyrrolopyrrole-Zinc Porphyrin that Delivers 900 nm Emission in Light-Emitting Electrochemical Cells
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2019 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 31, no 23, p. 9721-9728Article in journal (Refereed) Published
Abstract [en]

The development and application of a deep near-infrared (NIR) emitting star-shaped diketopyrrolopyrrole–Zn-porphyrin compound, ZnP(TDPP)4, is reported. The structure, conjugation, and planarity of the porphyrin compound were carefully tuned by molecular design, which resulted in a low-energy photoluminescence peak at 872 nm. The ZnP(TDPP)4 compound was employed as the emissive guest in light-emitting electrochemical cells (LECs), which also comprised the conjugated polymer poly[1,3-bis(2-ethylhexyl)-5-(5-(6-methyl-4,8-bis(5-(tributylsilyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophen-2-yl)thiophen-2-yl)-7-(5-methylthiophen-2-yl)-4H,8H-benzo[1,2-c:4,5-c′]dithiophene-4,8-dione] (PBDTSi-BDD) as the majority host, an ionic liquid as the electrolyte, and two air-stabile electrodes. These systematically optimized host–guest LECs featured a peak electroluminescence at 900 nm, which was delivered at a significant radiance of 36 μW/cm2 and at a low drive voltage of 3.8 V. It is notable that this is the most redshifted NIR emission attained from an LEC device to date, and as such, this work introduces Zn porphyrins as a sustainable and tunable option for emerging emissive NIR applications.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:umu:diva-167055 (URN)10.1021/acs.chemmater.9b03312 (DOI)000502418000015 ()
Funder
Swedish Foundation for Strategic Research The Kempe FoundationsSwedish Research CouncilSwedish Research Council FormasWallenberg Foundations, 2017.0186Wallenberg Foundations, 2016.0059
Available from: 2020-01-09 Created: 2020-01-09 Last updated: 2020-01-09Bibliographically approved
Iqbal, J., Enevold, J., Larsen, C., Wang, J., Revoju, S., Barzegar, H. R., . . . Edman, L. (2016). An arylene-vinylene based donor-acceptor-donor small molecule for the donor compound in high-voltage organic solar cells. Solar Energy Materials and Solar Cells, 155, 348-355
Open this publication in new window or tab >>An arylene-vinylene based donor-acceptor-donor small molecule for the donor compound in high-voltage organic solar cells
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2016 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 155, p. 348-355Article in journal (Refereed) Published
Abstract [en]

A donor-acceptor-donor (D-A-D) molecule has been designed and synthesized for use as the electron donating material in solution-processed small-molecule organic solar cells (OSCs). The D-A-D molecule comprises a central electron-accepting (2Z,2'Z)-2,2'-(2,5-bis(octyloxy)-1,4-phenylene)bis(3-(thiophen-2-yl)acry lonitrile) (ZOPTAN) core, which is chemically connected to two peripheral and electron-donating triphenylamine (TPA) units. The ZOPTAN-TPA molecule features a low HOMO level of -5.2 eV and an optical energy gap of 2.1 eV. Champion OSCs based on a solution-processed and non-annealed active material blend of [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) and ZOPTAN-TPA in a mass ratio of 2:1 exhibits a power conversion efficiency of 1.9% and a high open-circuit voltage of 1.0 V. 

Keywords
Organic solar cell, Small-molecule donor, Fullerene acceptor, Solution processing, High open-circuit ltage, Thermal stability
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-126290 (URN)10.1016/j.solmat.2016.06.018 (DOI)000381529100040 ()
Projects
Wallenberg 2011.0055
Note

Originally included in Christian Larsens thesis with title [An Arylene-Vinylene Based Donor-Acceptor-Donor Small Molecule for the DonorCompound in High-Voltage Organic Solar Cells].

Available from: 2016-11-08 Created: 2016-10-03 Last updated: 2019-12-18Bibliographically approved
Mindemark, J., Tang, S., Wang, J., Kaihovirta, N., Brandell, D. & Edman, L. (2016). High-Performance Light-Emitting Electrochemical Cells by Electrolyte Design. Chemistry of Materials, 28(8), 2618-2623
Open this publication in new window or tab >>High-Performance Light-Emitting Electrochemical Cells by Electrolyte Design
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2016 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 28, no 8, p. 2618-2623Article in journal (Refereed) Published
Abstract [en]

Polymer light-emitting electrochemical cells (LECs) are inherently dependent on a suitable electrolyte for proper function. Here, we design and synthesize a series of alkyl carbonate-capped star-branched oligoether-based electrolytes with large electrochemical stability windows, facile ion release, and high compatibility with common light-emitting materials. LECs based on such designed electrolytes feature fast turn-on, a long operational lifetime of 1400 h at >100 cd m(-2) and a record-high power conversion efficiency of 18.1 lm W-1, when equipped with an external outcoupling film.

National Category
Polymer Chemistry
Identifiers
urn:nbn:se:umu:diva-121575 (URN)10.1021/acs.chemmater.5b04847 (DOI)000375244500018 ()
Available from: 2016-06-27 Created: 2016-06-03 Last updated: 2018-06-07Bibliographically approved
Sharifi, T., Larsen, C., Wang, J., Kwong, W. L., Gracia-Espino, E., Mercier, G., . . . Edman, L. (2016). Toward a Low-Cost Artificial Leaf: Driving Carbon-Based and Bifunctional Catalyst Electrodes with Solution-Processed Perovskite Photovoltaics. Advanced Energy Materials, 6(20), 1-10, Article ID 1600738.
Open this publication in new window or tab >>Toward a Low-Cost Artificial Leaf: Driving Carbon-Based and Bifunctional Catalyst Electrodes with Solution-Processed Perovskite Photovoltaics
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2016 (English)In: Advanced Energy Materials, ISSN 1614-6832, Vol. 6, no 20, p. 1-10, article id 1600738Article in journal (Refereed) Published
Abstract [en]

Molecular hydrogen can be generated renewably by water splitting with an artificial-leaf device, which essentially comprises two electrocatalyst electrodes immersed in water and powered by photovoltaics. Ideally, this device should operate efficiently and be fabricated with cost-efficient means using earth-abundant materials. Here, a lightweight electrocatalyst electrode, comprising large surface-area NiCo2O4 nanorods that are firmly anchored onto a carbon-paper current collector via a dense network of nitrogen-doped carbon nanotubes is presented. This electrocatalyst electrode is bifunctional in that it can efficiently operate as both anode and cathode in the same alkaline solution, as quantified by a delivered current density of 10 mA cm(-2) at an overpotential of 400 mV for each of the oxygen and hydrogen evolution reactions. By driving two such identical electrodes with a solution-processed thin-film perovskite photovoltaic assembly, a wired artificial-leaf device is obtained that features a Faradaic H-2 evolution efficiency of 100%, and a solar-to-hydrogen conversion efficiency of 6.2%. A detailed cost analysis is presented, which implies that the material-payback time of this device is of the order of 100 days.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2016
Keywords
artificial-leaf devices, bifunctional electrocatalyst, carbon paper, nitrogen-doped carbon nanotubes, perovskite photovoltaics
National Category
Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-128457 (URN)10.1002/aenm.201600738 (DOI)000387136300001 ()
Available from: 2017-01-11 Created: 2016-12-05 Last updated: 2019-10-17Bibliographically approved
Wang, J., Tang, S., Sandström, A. & Edman, L. (2015). Combining an Ionic Transition Metal Complex with a Conjugated Polymer for Wide-Range Voltage-Controlled Light-Emission Color. ACS Applied Materials and Interfaces, 7(4), 2784-2789
Open this publication in new window or tab >>Combining an Ionic Transition Metal Complex with a Conjugated Polymer for Wide-Range Voltage-Controlled Light-Emission Color
2015 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 4, p. 2784-2789Article in journal (Refereed) Published
Abstract [en]

We report on voltage-controlled electroluminescence (EL) over a broad range of colors from a two-luminophor (2L) light-emitting electrochemical cell (LEC), comprising a blend of a majority blue-emitting conjugated polymer (blue-CP), a minority red-emitting ionic transition metal complex (red-iTMC), and an ion-transporting compound as the active layer. The EL color is reversibly shifted from red, over orange, pink, and white, to blue by simply changing the applied voltage from 3 to 7 V. An analysis of our results suggests that the low concentration of immobile cations intrinsic to this particular device configuration controls the electron injection and thereby the EL color: at low voltage, electrons are selectively injected into the low-barrier minority red-iTMC, but with increasing voltage the injection into the high-barrier majority blue-CP is gradually improved.

Keywords
light-emitting electrochemical cell, tunable color, conjugated polymer, ionic transition metal complex, ite emission, charge injection
National Category
Nano Technology
Identifiers
urn:nbn:se:umu:diva-102291 (URN)10.1021/am507967b (DOI)000349137300077 ()25574684 (PubMedID)
Available from: 2015-06-24 Created: 2015-04-23 Last updated: 2018-06-07Bibliographically approved
Wang, J., Enevold, J. & Edman, L. (2013). Photochemical Transformation of Fullerenes. Advanced Functional Materials, 23(25), 3220-3225
Open this publication in new window or tab >>Photochemical Transformation of Fullerenes
2013 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 23, no 25, p. 3220-3225Article in journal (Refereed) Published
Abstract [en]

Experimental findings and associated theoretical insights regarding the photochemical transformation of fullerenes are reported, which challenge the conventional wisdom in the field and point out a viable path towards improved fullerene-based electronic devices. It is shown that the efficiency of the photochemical monomer-to-dimer transformation of the fullerene [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) is strongly dependent on the light intensity, and this is utilized to demonstrate that direct patterning of an electroactive PCBM film can be effectuated by sub-second UV-light exposure followed by development in a tuned developer solution. By straightforward analytical reasoning, it is demonstrated that the observed intensity-dependent monomer-to-dimer transformation dictates that a significant back-reaction to the ground state must be in effect, which presumably originates from the excited-triplet state. By a combination of numerical modeling and analytical argumentation, it is further shown that the final dimer formation must constitute a bi-excited reaction between two neighboring monomers photo-excited to the triplet state.

Keywords
PCBM, fullerenes, patterning, photochemical transformation, dimerization, bi-excited reaction, organic electronics
National Category
Physical Sciences
Identifiers
urn:nbn:se:umu:diva-79609 (URN)10.1002/adfm.201203386 (DOI)000322362500010 ()
Projects
Wallenberg 2011.0055
Available from: 2013-10-17 Created: 2013-08-26 Last updated: 2019-12-18Bibliographically approved
Larsen, C., Wang, J. & Edman, L. (2012). Complementary ring oscillator fabricated via direct laser-exposure and solution-processing of a single-layer organic film. Thin Solid Films, 520(7), 3009-3012
Open this publication in new window or tab >>Complementary ring oscillator fabricated via direct laser-exposure and solution-processing of a single-layer organic film
2012 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 520, no 7, p. 3009-3012Article in journal (Refereed) Published
Abstract [en]

A complementary ring oscillator is realized by exposing a solution-processed single-layer organic film to area-selective laser-light exposure and solution development. The pristine film comprises a blend of two organic semiconductors: p-type poly(3-hexylthiophene-2,5-diyl) (P3HT) and n-type [6,6]-phenyl C-61 butyric acid methyl ester (PCBM). The exposure transforms PCBM into an insoluble form, and the subsequent development selectively removes the non-exposed PCBM while leaving exposed PCBM and P3HT intact. The 5-step ring oscillator exhibits a frequency of 10 mHz, a power delay product of 2.0 mu J, and an energy delay product of 22 mu Js. Opportunities for performance improvements of the scalable fabrication technique are highlighted in an accompanying analysis.

Keywords
CMOS, Ring-oscillator, Inverter, Organic thin-film transistor, Patterning, Energy delay product, P3HT, PCBM
National Category
Physical Sciences
Identifiers
urn:nbn:se:umu:diva-55400 (URN)10.1016/j.tsf.2011.12.048 (DOI)000301085100107 ()
Available from: 2012-05-15 Created: 2012-05-14 Last updated: 2018-06-08Bibliographically approved
Wang, J., Larsen, C., Wågberg, T. & Edman, L. (2011). Direct UV patterning of electronically active fullerene films. Advanced Functional Materials, 21(19), 3723-3728
Open this publication in new window or tab >>Direct UV patterning of electronically active fullerene films
2011 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 21, no 19, p. 3723-3728Article in journal (Refereed) Published
Abstract [en]

We utilize UV light for the attainment of high-resolution, electronically active patterns in [6,6]-phenyl C61-butyric acid methyl ester (PCBM) films. The patterns are created by directly exposing selected parts of a solution-cast PCBM film to UV light, and thereafter developing the film by immersing it in a tuned developer solution. We demonstrate that it is possible to attain complex, large-area PCBM structures with a smallest demonstrated-feature size of 1 μm by this method, and that the patterned PCBM material exhibits a high average electron mobility (1.2 × 10−2 cm2 V−1 s−1) in transistor experiments. The employment of UV light for direct patterning of PCBM for electronic applications is attractive, because PCBM exhibits high absorption in the UV range, and no sacrificial photoresist is needed. The patterning is achieved through the transformation by UV light of the soluble PCBM monomers into insoluble dimers with retained attractive electronic properties.

Place, publisher, year, edition, pages
Weinheim, Germany: Wiley-VCH Verlag GmbH, 2011
Keywords
Resist-free patterning, UV light, organic semiconductors, fullerenes, organic field-effect transistors
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-48545 (URN)10.1002/adfm.201100568 (DOI)000295224900015 ()
Available from: 2011-10-21 Created: 2011-10-21 Last updated: 2018-06-08Bibliographically approved
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