| 1. |
- Du, Siying, et al.
(författare)
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Nonfullerene acceptors from thieno[3,2-b]thiophene-fused naphthalene donor core with six-member-ring connection for efficient organic solar cells
- 2021
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Ingår i: Dyes and Pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 185
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Tidskriftsartikel (refereegranskat)abstract
- Comprehensive design ideas on the fused-ring donor-core in state-of-the-art acceptor-donor-acceptor (A-D-A) nonfullerene acceptors (NFAs) are still of great importance for regulating the electron push-pull effect for the sake of optimal light-harvesting, frontier molecular orbital levels, and finally their photovoltaic properties. Herein, thieno[3,2-b]thiophenes were fused in bay-area of naphthalene via six-member-ring connection, resulting in the formation of dihydropyrenobisthieno[3,2-b]thiophene based octacyclic ladder-type donor core, which was flanked by two 1,1-dicyanomethylene-3-indanone (IC) acceptor motifs with and without 5,6-diflourination, namely PTT-IC and PTT-2FIC, respectively, as novel efficient A-D-A fused-ring electron acceptors (FREAs). Compared with PTT-IC, fluorinated PTT-2FIC possesses narrower optical bandgap of 1.48 eV, better π-π stacking, and its PBDB-T:PTT-2FIC blend film exhibited better morphology, and better hole and electron mobility. As a result, nonfullerene solar cells using PBDB-T:PTT-2FIC as the active layer achieved a decent PCE of 10.40%, with an open-circuit voltage (VOC) of 0.87 V, a fill factor (FF) of 0.65, and a much higher short-circuit current (JSC) of 18.26 mA/cm2. Meanwhile, the PBDB-T:PTT-IC cells delivered a lower JSC of 12.58 mA/cm2 but a higher VOC of 0.99 V, thus resulting in a PCE of 7.39% due to its wider optical bandgap of 1.58 eV and higher LUMO energy level. These results demonstrated that NFAs based on fused-ring donor core from fusing thieno[3,2-b]thiophenes with naphthalene via six-member-ring connection are promising for organic photovoltaic applications.
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| 2. |
- Hu, Wei, et al.
(författare)
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Axisymmetric and Asymmetric Naphthalene-Bisthienothiophene Based Nonfullerene Acceptors: On Constitutional Isomerization and Photovoltaic Performance
- 2020
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 3:6, s. 5734-5744
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Tidskriftsartikel (refereegranskat)abstract
- Two pairs of constitutional isomers of fused-octacyclic nonfullerene acceptors (NFAs) based on a naphthalene-bisthienothiophene core with or without fluorination at the ending groups have been developed. Compared with the axisymmetric NFAs N66-IC and N66-2FIC with two six-member-ring bridges, their asymmetric constitutional isomers N65-IC and N65-2FIC both with one six-member-ring bridge and one five-member-ring bridge exhibit remarkable red-shifted absorption, higher crystallinity, and slightly down-shifted LUMO energy levels. Organic solar cells based on PBDB-T-2F:N65-2FIC achieved a promising power conversion efficiency of 10.19%, which is three times higher than that of its counterpart PBDB-T-2F:N66-2FIC cell (3.46%). While being blended with PBDB-T as the donor material, the asymmetric acceptor analogue N65-IC based solar cell pronounces a PCE of 9.03%, being significantly improved from that of 5.45% for the PBDB-T:N66-IC based cell, which is in consistency with the results from those cells from their both fluorinated donor and acceptor counterparts. Design rules on either both fluorinated, both nonfluorinated, or cross-combined donor/acceptors for device fabrication has been explored. In addition, PBDB-T-2F:N65-2FIC possesses very promising device stability with 85% of its initial PCE after an exposure time of 1500 h under one sun illumination, which is meaningful for their future commercial devices.
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| 3. |
- Liu, Shungang, et al.
(författare)
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The role of connectivity in significant bandgap narrowing for fused-pyrene based non-fullerene acceptors toward high-efficiency organic solar cells
- 2020
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 8:12, s. 5995-6003
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Tidskriftsartikel (refereegranskat)abstract
- Great attention has been paid to developing low bandgap non-fullerene acceptors (NFAs) for matching wide bandgap donor polymers to increase the photocurrent and therefore the power conversion efficiencies (PCEs) of NFA organic solar cells, while pyrene-core based acceptor-donor-acceptor (A-D-A) NFAs have been mainly reported via the 2,9-position connection due to their bisthieno[3′,2′-b']thienyl[a,h]pyrene fused via a five-membered ring bridge at the ortho-position of pyrene as the representative one named FPIC5, which has prohibited further narrowing their energy gap. Herein, an acceptor FPIC6 was exploited by creating the 1,8-position connection through fusing as bisthieno[3′,2′-b′]thienyl[f-g,m-n]pyrene linked at the bay-position via a six-membered bridge, with enhanced push-pull characteristics within such A-D-A structure. As a structural isomer of FPIC5, FPIC6 exhibited a much lower bandgap of 1.42 eV (1.63 eV for FPIC5). Therefore, the photocurrent and PCE of PTB7-Th:FPIC6 cells were improved to 21.50 mA cm-2 and 11.55%, respectively, due to the balanced mobilities, better photoluminescence quenching efficiency and optimized morphology, which are both ∼40% better than those of PTB7-Th:FPIC5 cells. Our results clearly proved that a pyrene fused core with 1,8-position connection with electron-withdrawing end groups instead of 2,9-position connection is an efficient molecular design strategy to narrow the optical bandgap and improve the photovoltaic performance of NFA based OSCs.
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| 4. |
- Wishart, David S., et al.
(författare)
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HMDB 5.0 : the Human Metabolome Database for 2022
- 2022
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Ingår i: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 50:D1, s. D622-D631
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Tidskriftsartikel (refereegranskat)abstract
- The Human Metabolome Database or HMDB (https://hmdb.ca) has been providing comprehensive reference information about human metabolites and their associated biological, physiological and chemical properties since 2007. Over the past 15 years, the HMDB has grown and evolved significantly to meet the needs of the metabolomics community and respond to continuing changes in internet and computing technology. This year's update, HMDB 5.0, brings a number of important improvements and upgrades to the database. These should make the HMDB more useful and more appealing to a larger cross-section of users. In particular, these improvements include: (i) a significant increase in the number of metabolite entries (from 114 100 to 217 920 compounds); (ii) enhancements to the quality and depth of metabolite descriptions; (iii) the addition of new structure, spectral and pathway visualization tools; (iv) the inclusion of many new and much more accurately predicted spectral data sets, including predicted NMR spectra, more accurately predicted MS spectra, predicted retention indices and predicted collision cross section data and (v) enhancements to the HMDB's search functions to facilitate better compound identification. Many other minor improvements and updates to the content, the interface, and general performance of the HMDB website have also been made. Overall, we believe these upgrades and updates should greatly enhance the HMDB's ease of use and its potential applications not only in human metabolomics but also in exposomics, lipidomics, nutritional science, biochemistry and clinical chemistry.
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| 5. |
- Xie, Liang, et al.
(författare)
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Low-bandgap nonfullerene acceptor based on thieno[3,2-b]indole core for highly efficient binary and ternary organic solar cells
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 427
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Tidskriftsartikel (refereegranskat)abstract
- A low-bandgap nonfullerene acceptor (NFA) TIT-2FIC based on thieno[3,2-b]indole-thiophenes core has been developed. Compared with the analogue NFAs DTC(4Ph)-4FIC and IT-4F, TIT-2FIC exhibited remarkably red-shifted absorption, and up-shifted HOMO energy level. In addition, TIT-2FIC showed interesting universal miscibility with the donors nonfluorinated PBDB-T and fluorinated PM6, therefore the corresponding organic solar cells achieved promising power conversion efficiencies (PCEs) of 11.80% and 13.00%, respectively, which are higher compared to the counterpart IT-4F based cells. Furthermore, the ternary PM6:TIT-2FIC:Y6 cell pronounced a high PCE of 17.22%, being significantly improved from that of 16.04% for the binary PM6:Y6 cell. Similar improvement in PCEs from 13.41% to 14.46% was also observed in the ternary PM6:TIT-2FIC:IT-4F cell with TIT-2FIC as the third component. These results indicated that TIT-2FIC is universally applicable as an acceptor with nonfluorinated or fluorinated polymer donor materials in both binary and ternary cells.
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