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- Genene, Zewdneh, 1983, et al.
(författare)
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Comparative study on the effects of alkylsilyl and alkylthio side chains on the performance of fullerene and non-fullerene polymer solar cells
- 2020
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Ingår i: Organic Electronics: physics, materials, applications. - : Elsevier BV. - 1566-1199. ; 77
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Tidskriftsartikel (refereegranskat)abstract
- Two novel high gap donor polymers – PBDTTSi-TzBI and PBDTTS-TzBI, based on imide-fused benzotriazole (TzBI) with asymmetric side chains and alkylsilyl (Si) or alkylthio (S) substituted 4,8-di(thien-2-yl)benzo-[1,2-b:4,5-b′]dithiophene (BDTT) – are successfully synthesized. The effect of the side chain variation on the photophysical, morphological and photovoltaic properties of blends of these polymers with fullerene and non-fullerene acceptors is investigated. The PBDTTSi-TzBI polymer shows a deeper highest occupied molecular orbital energy level, which results in higher open-circuit voltages. Nevertheless, the polymer solar cells fabricated using PBDTTS-TzBI in combination with PC71BM afford a higher power conversion efficiency of 7.3% (vs 4.0% for PBDTTSi-TzBI:PC71BM). By using the non-fullerene acceptor ITIC, the absorption of the blends extends to 850 nm and better device efficiencies are achieved, 6.9% and 9.6% for PBDTTSi-TzBI:ITIC and BDTTS-TzBI:ITIC, respectively. The better performance of the PBDTTS-TzBI:ITIC-based devices is attributed to the strong and broad absorption and balanced charge transport, and is among the best performances reported for non-fullerene solar cells based on TzBI-containing polymer donors.
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| 2. |
- Murto, Petri Henrik, 1984, et al.
(författare)
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Incorporation of Designed Donor−Acceptor−Donor Segments in a Host Polymer for Strong Near-Infrared Emission from a Large-Area Light-Emitting Electrochemical Cell
- 2018
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 1:4, s. 1753-1761
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Tidskriftsartikel (refereegranskat)abstract
- Cost-efficient thin-film devices that emit in the nearinfrared (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)-4 H -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 μ W/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.
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| 3. |
- Negash, Asfaw, et al.
(författare)
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Diketopyrrolopyrrole-based terpolymers with tunable broad band absorption for fullerene and fullerene-free polymer solar cells
- 2019
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Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry (RSC). - 2050-7534 .- 2050-7526. ; 7:11, s. 3375-3384
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Tidskriftsartikel (refereegranskat)abstract
- A series of random terpolymers with donor-acceptor-donor-acceptor molecular configuration, comprising fluorinated benzotriazole (FTAZ) and thienothiophene-capped diketopyrrolopyrrole (TTDPP) as the first and second electron-accepting moieties and thienyl-substituted benzodithiophene (BDTT) as the electron-donating unit, are designed for polymer solar cells. By tuning the ratio of TTDPP and FTAZ, the optoelectronic properties of the terpolymers are systematically varied. All materials exhibit a broad absorption window spanning from 300 to 900 nm, illustrating the success of the terpolymer approach. Fullerene-based polymer solar cells fabricated from the terpolymer with the highest content of TTDPP afford a power conversion efficiency of 5.7%, with a short-circuit current density of 15.2 mA cm -2 . On the other hand, solar cell devices composed of the terpolymer with the lowest content of TTDPP and the narrow gap non-fullerene acceptor IEICO-4F exhibit a higher efficiency of 6.3%, with an enhanced short-circuit current density of 17.5 mA cm -2 , as a result of a better complementarity in the absorption of the donor and acceptor materials and well-balanced charge carrier mobilities. This efficiency represents the best value for fullerene-free polymer solar cells based on DPP-containing polymers to date.
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