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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
Murto, P., Tang, S., Larsen, C., Xu, X., Sandström, A., Pietarinen, J., . . . Edman, L. (2018). Incorporation of Designed Donor-Acceptor-Donor Segments in a Host Polymer for Strong Near-Infrared Emission from a Large-Area Light-Emitting Electrochemical Cell. ACS Applied Energy Materials, 1(4), 1753-1761
Open this publication in new window or tab >>Incorporation of Designed Donor-Acceptor-Donor Segments in a Host Polymer for Strong Near-Infrared Emission from a Large-Area Light-Emitting Electrochemical Cell
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2018 (English)In: ACS Applied Energy Materials, ISSN 2574-0962, Vol. 1, no 4, p. 1753-1761Article in journal (Refereed) Published
Abstract [en]

Cost-efficient thin-film devices that emit in the near-infrared (NIR) range promise a wide range of important applications. Here, the synthesis and NIR application of a series of copolymers comprising poly[indacenodithieno[3,2-b]thiophene-2,8-diyl] (PIDTT) as the host and different donor–acceptor–donor (DAD) segments as the guest are reported. We find that a key design criterion for efficient solid-state host-to-guest energy transfer is that the DAD conformation is compatible with the conformation of the host. Such host–guest copolymers are evaluated as the emitter in light-emitting electrochemical cells (LECs) and organic light-emitting diodes, and the best performance is invariably attained from the LEC devices because of the observed balanced electrochemical doping that alleviates issues with a noncentered emission zone. An LEC device comprising a host–guest copolymer with 4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b′]dithiophene as the donor and benzo[c][1,2,5]thiadiazole as the acceptor delivers an impressive near-infrared (NIR) performance in the form of a high radiance of 1458 μW/cm2 at a peak wavelength of 725 nm when driven by a current density of 500 mA/cm2, a second-fast turn-on, and a good stress stability as manifested in a constant radiance output during 3 days of uninterrupted operation. The high-molecular-weight copolymer features excellent processability, and the potential for low-cost and scalable NIR applications is verified through a spray-coating fabrication of a >40 cm2 large-area device, which emits intense and uniform NIR light at a low drive voltage of 4.5 V.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
near-infrared, NIR, large-area device, light-emitting electrochemical cell, LEC, copolymer, solution processing
Identifiers
urn:nbn:se:umu:diva-157352 (URN)10.1021/acsaem.8b00283 (DOI)000458705400044 ()
Funder
Swedish Foundation for Strategic Research Swedish Research CouncilSwedish Energy AgencySwedish Research Council Formas
Available from: 2019-03-15 Created: 2019-03-15 Last updated: 2019-03-15Bibliographically approved
Murto, P., Tang, S., Larsen, C., Xu, X., Sandström, A., Pietarinen, J., . . . Edman, L. (2018). Incorporation of Designed Donor-Acceptor-Donor Segments in a Host Polymer for Strong Near-Infrared Emission from a Large-Area Light-Emitting Electrochemical Cell. ACS Applied Energy Materials, 1(4), 1753-1761
Open this publication in new window or tab >>Incorporation of Designed Donor-Acceptor-Donor Segments in a Host Polymer for Strong Near-Infrared Emission from a Large-Area Light-Emitting Electrochemical Cell
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2018 (English)In: ACS Applied Energy Materials, ISSN 2574-0962, Vol. 1, no 4, p. 1753-1761Article in journal (Refereed) Published
Abstract [en]

Cost-efficient thin-film devices that emit in the near infrared (NIR) range promise a wide range of important applications. Here, the synthesis and NIR application of a series of copolymers comprising poly[indacenodithieno[3,2-b]thiophene-2,8-diyl] (PIDTT) as the host and different donor acceptor donor (DAD) segments as the guest are reported. We find that a key design criterion for efficient solid-state host-to-guest energy transfer is that the DAD conformation is compatible with the conformation of the host. Such host guest copolymers are evaluated as the emitter in light-emitting electrochemical cells (LECs) and organic light-emitting diodes, and the best performance is invariably attained from the LEC devices because of the observed balanced electrochemical doping that alleviates issues with a noncentered emission zone. An LEC device comprising a host guest copolymer with 4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophene as the donor and benzo[c][1,2,5]thiadiazole as the acceptor delivers an impressive near-infrared (NIR) performance in the form of a high radiance of 1458 mu W/cm(2) at a peak wavelength of 725 nm when driven by a current density of 500 mA/cm(2), a second-fast turn-on, and a good stress stability as manifested in a constant radiance output during 3 days of uninterrupted operation. The high-molecular-weight copolymer features excellent processability, and the potential for low-cost and scalable NIR applications is verified through a spray-coating fabrication of a >40 cm(2) large-area device, which emits intense and uniform NIR light at a low drive voltage of 4.5 V.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
near-infrared, NIR, large-area device, light-emitting electrochemical cell, LEC, copolymer, solution processing
National Category
Polymer Chemistry Other Chemistry Topics
Identifiers
urn:nbn:se:umu:diva-156904 (URN)10.1021/acsaem.8b00283 (DOI)000458705400044 ()
Available from: 2019-04-16 Created: 2019-04-16 Last updated: 2019-04-16Bibliographically approved
Enevold, J., Larsen, C., Zakrisson, J., Andersson, M. & Edman, L. (2018). Realizing large-area arrays of semiconducting fullerene nanostructures with direct laser interference patterning. Nano letters (Print), 18(1), 540-545
Open this publication in new window or tab >>Realizing large-area arrays of semiconducting fullerene nanostructures with direct laser interference patterning
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2018 (English)In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 18, no 1, p. 540-545Article in journal (Refereed) Published
Keywords
semiconducting nanostructure, mask- and resist-free patterning, laser interference lithography, fullerenes, phenyl-C 61-butyric acid methyl ester (PCBM), high contrast
National Category
Other Physics Topics
Identifiers
urn:nbn:se:umu:diva-143439 (URN)10.1021/acs.nanolett.7b04568 (DOI)000420000000073 ()29232948 (PubMedID)
Available from: 2017-12-28 Created: 2017-12-28 Last updated: 2018-06-09Bibliographically approved
Barzegar, H. R., Larsen, C., Boulanger, N., Zettl, A., Edman, L. & Wågberg, T. (2018). Self-assembled PCBM nanosheets: a facile route to electronic layer-on-Layer heterostructures. Nano letters (Print), 18(2), 1442-1447
Open this publication in new window or tab >>Self-assembled PCBM nanosheets: a facile route to electronic layer-on-Layer heterostructures
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2018 (English)In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 18, no 2, p. 1442-1447Article in journal, Editorial material (Refereed) Published
Abstract [en]

We report on the self-assembly of semicrystalline [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) nanosheets at the interface between a hydrophobic solvent and water, and utilize this opportunity for the realization of electronically active organic/organic molecular heterostructures. The self-assembled PCBM nanosheets can feature a lateral size of >1 cm2 and be transferred from the water surface to both hydrophobic and hydrophilic surfaces using facile transfer techniques. We employ a transferred single PCBM nanosheet as the active material in a field-effect transistor (FET) and verify semiconductor function by a measured electron mobility of 1.2 × 10–2 cm2 V–1 s–1 and an on–off ratio of ∼1 × 104. We further fabricate a planar organic/organic heterostructure with the p-type organic semiconductor poly(3-hexylthiophene-2,5-diyl) as the bottom layer and the n-type PCBM nanosheet as the top layer and demonstrate ambipolar FET operation with an electron mobility of 8.7 × 10–4 cm2 V–1 s–1 and a hole mobility of 3.1 × 10–4 cm2V–1 s–1.

Keywords
Organic electronic; organic heterostructures; PCBM nanosheets; self-assembly
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-144566 (URN)10.1021/acs.nanolett.7b05205 (DOI)000425559700114 ()29364679 (PubMedID)
Available from: 2018-02-06 Created: 2018-02-06 Last updated: 2018-06-13Bibliographically approved
Larsen, C., Forchheimer, R., Edman, L. & Tu, D. (2017). Design, fabrication and application of organic power converters: Driving light-emitting electrochemical cells from the AC mains. Organic electronics, 45, 57-64
Open this publication in new window or tab >>Design, fabrication and application of organic power converters: Driving light-emitting electrochemical cells from the AC mains
2017 (English)In: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 45, p. 57-64Article in journal (Refereed) Published
Abstract [en]

The design, fabrication and operation of a range of functional power converter circuits, based on diode configured organic field-effect transistors as the rectifying unit and capable of transforming a high AC input voltage to a selectable DC voltage, are presented. The converter functionality is demonstrated by selecting and tuning its constituents so that it can effectively drive a low-voltage organic electronic device, a light-emitting electrochemical cell (LEC), when connected to high-voltage AC mains. It is established that the preferred converter circuit for this task comprises an organic full-wave rectifier and a regulation resistor but is void of a smoothing capacitor, and that such a circuit connected to the AC mains (230 V, 50 Hz) successfully can drive an LEC to bright luminance (360 cd m(-2)) and high efficiency (6.4 cd A(-1)).

Keywords
Organic power converters, Diode-configured organic field-effect transistors, Light-emitting electrochemical cells, Solution processing, Organic rectifiers
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Other Medical Biotechnology
Identifiers
urn:nbn:se:umu:diva-136051 (URN)10.1016/j.orgel.2017.02.036 (DOI)000401042600008 ()
Available from: 2017-06-20 Created: 2017-06-20 Last updated: 2018-06-09Bibliographically approved
Tang, S., Sandström, A., Lundberg, P., Lanz, T., Larsen, C., van Reenen, S., . . . Edman, L. (2017). Design rules for light-emitting electrochemical cells delivering bright luminance at 27.5 percent external quantum efficiency. Nature Communications, 8, Article ID 1190.
Open this publication in new window or tab >>Design rules for light-emitting electrochemical cells delivering bright luminance at 27.5 percent external quantum efficiency
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2017 (English)In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, article id 1190Article in journal (Refereed) Published
Abstract [en]

The light-emitting electrochemical cell promises cost-efficient, large-area emissive applications, as its characteristic in-situ doping enables use of air-stabile electrodes and a solution-processed single-layer active material. However, mutual exclusion of high efficiency and high brightness has proven a seemingly fundamental problem. Here we present a generic approach that overcomes this critical issue, and report on devices equipped with air-stabile electrodes and outcoupling structure that deliver a record-high efficiency of 99.2 cd A(-1) at a bright luminance of 1910 cd m(-2). This device significantly outperforms the corresponding optimized organic light-emitting diode despite the latter employing calcium as the cathode. The key to this achievement is the design of the host-guest active material, in which tailored traps suppress exciton diffusion and quenching in the central recombination zone, allowing efficient triplet emission. Simultaneously, the traps do not significantly hamper electron and hole transport, as essentially all traps in the transport regions are filled by doping.

Place, publisher, year, edition, pages
Nature Publishing Group, 2017
National Category
Other Physics Topics Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-141807 (URN)10.1038/s41467-017-01339-0 (DOI)000413894100012 ()29085078 (PubMedID)
Available from: 2017-11-27 Created: 2017-11-27 Last updated: 2018-06-09Bibliographically approved
Tang, S., Murto, P., Xu, X., Larsen, C., Wang, E. & Edman, L. (2017). Intense and Stable Near-Infrared Emission from Light-Emitting Electrochemical Cells Comprising a Metal-Free Indacenodithieno[3,2-b]thiophene-Based Copolymer as the Single Emitter. Chemistry of Materials, 29(18), 7750-7759
Open this publication in new window or tab >>Intense and Stable Near-Infrared Emission from Light-Emitting Electrochemical Cells Comprising a Metal-Free Indacenodithieno[3,2-b]thiophene-Based Copolymer as the Single Emitter
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2017 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 29, no 18, p. 7750-7759Article in journal (Refereed) Published
Abstract [en]

We report on the synthesis, characterization, and application of a series of metal-free near-infrared (NIR) emitting alternating donor/acceptor copolymers based on indacenodithieno[3,2-b]thiophene (IDTT) as the donor unit. A light-emitting electrochemical cell (LEC), comprising a blend of the copolymer poly[indacenodithieno[3,2-b]thiophene-2,8-diyl-alt-2,3-diphenyl-5,8-di(thiophen-2-y1)- quinoxaline-5,5'-diy1] and an ionic liquid as the single-layer active material sandwiched between two air-stable electrodes, delivered NIR emission (lambda(peak) = 705 nm) with a high radiance of 129 mu W/cm(2) when driven by a low voltage of 3.4 V. The NIR-LEC also featured good stress stability, as manifested in that the peak NIR output from a nonencapsulated device after 24 h of continuous operation only had dropped by 3% under N-2 atmosphere and by 27% under ambient air. This work accordingly introduces IDTT-based donor/acceptor copolymers as functional metal-free electroluminescent materials in NIR-emitting devices and also provides guidelines for how future NIR emitters should be designed for further improved performance.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2017
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:umu:diva-140905 (URN)10.1021/acs.chemmater.7b02049 (DOI)000411918900016 ()
Available from: 2017-11-16 Created: 2017-11-16 Last updated: 2018-06-09Bibliographically approved
Keshmiri, V., Larsen, C., Edman, L., Forchheimer, R. & Tu, D. (2016). A Current Supply with Single Organic Thin-Film Transistor for Charging Supercapacitors. In: Kuo, Y (Ed.), THIN FILM TRANSISTORS 13 (TFT 13): . Paper presented at 13th Symposium on Thin Film Transistor Technologies (TFT), OCT 03-05, 2016, Honolulu, HI (pp. 217-222). ELECTROCHEMICAL SOC INC, 75(10)
Open this publication in new window or tab >>A Current Supply with Single Organic Thin-Film Transistor for Charging Supercapacitors
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2016 (English)In: THIN FILM TRANSISTORS 13 (TFT 13) / [ed] Kuo, Y, ELECTROCHEMICAL SOC INC , 2016, Vol. 75, no 10, p. 217-222Conference paper, Published paper (Refereed)
Abstract [en]

We present a current supply, comprising a single organic thin-film transistor (OTFT), for the charging of supercapacitors. The current supply takes power from the electric grid (115 V AC, US standard), converts the AC voltage to a quasi-constant DC current (similar to 0.1 mA) regardless of the impedance of the load, and charges the supercapacitor. Solution-processed OTFTs based on the popular polymeric semiconductor poly(3-hexylthiophene- 2,5-diyl) have been developed to rectify the 115 V AC voltage. A diodeconfigured OTFT was used as a half-wave rectifier. The single OTFT current supply was demonstrated to charge a 220 mF supercapacitor to 1 V directly using 115 V AC voltage as the input. This work paves the road towards all-printable supercapacitor energy-storage systems with integrated chargers, which enable direct charging from a power outlet.

Place, publisher, year, edition, pages
ELECTROCHEMICAL SOC INC, 2016
Series
ECS Transactions, ISSN 1938-5862 ; 75
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:umu:diva-138633 (URN)10.1149/07510.0217ecst (DOI)000406512700030 ()978-1-60768-727-6 (ISBN)
Conference
13th Symposium on Thin Film Transistor Technologies (TFT), OCT 03-05, 2016, Honolulu, HI
Available from: 2017-08-31 Created: 2017-08-31 Last updated: 2018-06-09Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-2480-3786

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