1. |
- Chen, Youchun, et al.
(author)
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Insights into the working mechanism of cathode interlayers in polymer solar cells via [(C8H17)(4)N](4)[SiW12O40]
- 2016
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In: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 4:48, s. 19189-19196
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Journal article (peer-reviewed)abstract
- A low-cost (amp;lt;$1 per g), high-yield (amp;gt;90%), alcohol soluble surfactant-encapsulated polyoxometalate complex [(C8H17)(4)N](4)[SiW12O40] has been synthesized and utilized as a cathode interlayer (CIL) in polymer solar cells (PSCs). A power conversion efficiency of 10.1% can be obtained for PSCs based on PTB7-Th (poly[[2,6-4,8-di(5-ethylhexylthienyl) benzo[1,2-b;3,3-b]-dithiophene][3-fluoro-2[(2-ethylhexyl) carbonyl] thieno [3,4-b]-thiophenediyl]]):PC71BM ([6,6]-phenyl C71-butyric acidmethyl ester) due to the incorporation of [(C8H17)(4)N](4)[SiW12O40]. Combined measurements of current density-voltage characteristics, transient photocurrent, charge carrier mobility and capacitance-voltage characteristics demonstrate that [(C8H17)(4)N](4)[SiW12O40] can effectively increase the built-in potential, charge carrier density and mobility and accelerate the charge carrier extraction in PSCs. Most importantly, the mechanism of using [(C8H17)(4)N](4)[SiW12O40] as the CIL is further brought to light by X-ray photoemission spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) of the metal/ [(C8H17)(4)N](4)[SiW12O40] interface. The findings suggest that [(C8H17)(4)N](4)[SiW12O40] not only decreased the work function of the metal cathodes but also was n-doped upon contact with the metals, which provide insights into the working mechanism of the CILs simultaneously improving the open circuit voltage, short circuit current and fill factor in the PSCs.
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2. |
- Li, Yongxi, et al.
(author)
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A fused-ring based electron acceptor for efficient non-fullerene polymer solar cells with small HOMO offset
- 2016
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In: NANO ENERGY. - : ELSEVIER SCIENCE BV. - 2211-2855. ; 27, s. 430-438
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Journal article (peer-reviewed)abstract
- A non-fullerene electron acceptor bearing a novel backbone with fused 10-heterocyclic ring (in-dacenodithiopheno-indacenodiselenophene), denoted by IDTIDSe-IC is developed for fullerene free polymer solar cells. IDTIDSe-IC exhibits a low band gap (E-g=1.52 eV) and strong absorption in the 600850 nm region. Combining with a large band gap polymer J51 (E-g=1.91 eV) as donor, broad absorption coverage from 300 nm to 800 nm is obtained due to complementary absorption of J51 and IDTIDSe-IC, which enables a high PCE of 8.02% with a V-oc of 0.91 V, a J(SC) of 15.16 mA/cm(2) and a FF of 58.0% in the corresponding PSCs. Moreover, the EQE of 50-65% is achieved in the absorption range of IDTIDSe-IC with only about 0.1 eV HOMO difference between J51 and IDTIDSe-IC. (C) 2016 Elsevier Ltd. All rights reserved.
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3. |
- Li, Yongxi, et al.
(author)
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Non-fullerene acceptor with low energy loss and high external quantum efficiency: towards high performance polymer solar cells
- 2016
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In: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 4:16, s. 5890-5897
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Journal article (peer-reviewed)abstract
- A non-fullerene electron acceptor bearing a fused 10-heterocyclic ring (indacenodithiophenoindacenodithiophene) with a narrow band gap (similar to 1.5 eV) was designed and synthesized. It possesses excellent planarity and enhanced effective conjugation length compared to previously reported fused-ring electron acceptors. When this acceptor was paired with PTB7-Th and applied in polymer solar cells, a power conversion efficiency of 6.5% was achieved with a high open circuit voltage of 0.94 V. More significantly, an energy loss as low as 0.59 eV and an external quantum efficiency as high as 63% were obtained simultaneously.
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4. |
- Lin, Yuze, et al.
(author)
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Mapping Polymer Donors toward High-Efficiency Fullerene Free Organic Solar Cells
- 2017
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In: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 29:3
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Journal article (peer-reviewed)abstract
- Five polymer donors with distinct chemical structures and different electronic properties are surveyed in a planar and narrow-bandgap fused-ring electron acceptor (IDIC)-based organic solar cells, which exhibit power conversion efficiencies of up to 11%.
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5. |
- Fan, Qunping, 1989, et al.
(author)
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Fluorinated Photovoltaic Materials for High-Performance Organic Solar Cells
- 2019
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In: Chemistry - An Asian Journal. - : Wiley. - 1861-471X .- 1861-4728. ; 14:18, s. 3085-3095
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Research review (peer-reviewed)abstract
- Over the past decade, organic solar cells (OSCs) have achieved a dramatic boost in their power conversion efficiencies from about 6 % to over 16 %. In addition to developments in device engineering, innovative photovoltaic materials, especially fluorinated donors and acceptors, have become the dominant factor for improved device performance. This minireview highlights fluorinated photovoltaic materials that enable efficient OSCs. Impressive OSCs have been obtained by developing some important molds of fluorinated donor and acceptor systems. The molecular design strategy and the matching principle of fluorinated donors and acceptors in OSCs are discussed. Finally, a concise summary and outlook are presented for advances in fluorinated materials to realize the practical application of OSCs.
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6. |
- Tang, Ailing, et al.
(author)
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Simultaneously Achieved High Open-Circuit Voltage and Efficient Charge Generation by Fine-Tuning Charge-Transfer Driving Force in Nonfullerene Polymer Solar Cells
- 2018
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In: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 28:6
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Journal article (peer-reviewed)abstract
- To maximize the short-circuit current density (J(SC)) and the open circuit voltage (V-OC) simultaneously is a highly important but challenging issue in organic solar cells (OSCs). In this study, a benzotriazole-based p-type polymer (J61) and three benzotriazole-based nonfullerene small molecule acceptors (BTA1-3) are chosen to investigate the energetic driving force for the efficient charge transfer. The lowest unoccupied molecular orbital (LUMO) energy levels of small molecule acceptors can be fine-tuned by modifying the end-capping units, leading to high V-OC (1.15-1.30 V) of OSCs. Particularly, the LUMO energy level of BTA3 satisfies the criteria for efficient charge generation, which results in a high V-OC of 1.15 V, nearly 65% external quantum efficiency, and a high power conversion efficiency (PCE) of 8.25%. This is one of the highest V-OC in the high-performance OSCs reported to date. The results imply that it is promising to achieve both high J(SC) and V-OC to realize high PCE with the carefully designed nonfullerene acceptors.
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