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- Genene, Zewdneh, 1983, et al.
(author)
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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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In: Organic Electronics: physics, materials, applications. - : Elsevier BV. - 1566-1199. ; 77
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Journal article (peer-reviewed)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. |
- Negash, Asfaw, et al.
(author)
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Exploring the High-Temperature Window of Operation for Organic Photovoltaics: A Combined Experimental and Simulations Study
- 2024
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In: Advanced Materials for Optics and Electronics. - 1616-301X .- 1616-3028. ; 34:6
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Journal article (peer-reviewed)abstract
- The global climate change negatively affects the photovoltaic performance of traditional solar cell technologies. This article investigates the potential of organic photovoltaics (OPV) for high-temperature environments, ranging from urban hot summers (30—40 °C) and desert regions (65 °C) up to (aero) space conditions (130 °C), the thermal window in which OPV can operate. The approach is based on a combination of experiments and simulations up to 180 °C, moving significantly beyond the conventional temperature ranges reported in the literature. New 2H-benzo[d][1,2,3]triazole-5,6-dicarboxylic imide-based copolymers with decomposition onset temperatures above 340 °C are used for this study, in combination with non-fullerene acceptors. Contrary to their inorganic counterparts, OPV devices show a positive temperature coefficient up to ≈90 °C. At temperatures of 150 °C, they are still operational, retaining their room temperature efficiency. Complementary simulations are performed using an in-house developed software package that numerically solves the drift-diffusion equations to understand the general trends in the obtained current–voltage characteristics and the materials’ intrinsic behavior as a function of temperature. The presented methodology of combined high-temperature experiments and simulations can be further applied to investigate the thermal window of operation for other OPV material systems, opening novel high-temperature application routes.
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