Non-fullerene polymer solar cells (PSCs) with solution-processable n-type organic semiconductor (n-OS) as acceptor have seen rapid progress recently owing to the synthesis of new low bandgap n-OS, ...such as ITIC. To further increase power conversion efficiency (PCE) of the devices, it is of a great challenge to develop suitable polymer donor material that matches well with the low bandgap n-OS acceptors thus providing complementary absorption and nanoscaled blend morphology, as well as suppressed recombination and minimized energy loss. To address this challenge, we synthesized three medium bandgap 2D-conjugated bithienyl-benzodithiophene-alt-fluorobenzotriazole copolymers J52, J60, and J61 for the application as donor in the PSCs with low bandgap n-OS ITIC as acceptor. The three polymers were designed with branched alkyl (J52), branched alkylthio (J60), and linear alkylthio (J61) substituent on the thiophene conjugated side chain of the benzodithiophene (BDT) units for studying effect of the substituents on the photovoltaic performance of the polymers. The alkylthio side chain, red-shifted absorption down-shifted the highest occupied molecular orbital (HOMO) level and improved crystallinity of the 2D conjugated polymers. With linear alkylthio side chain, the tailored polymer J61 exhibits an enhanced J SC of 17.43 mA/cm2, a high V OC of 0.89 V, and a PCE of 9.53% in the best non-fullerene PSCs with the polymer as donor and ITIC as acceptor. To the best of our knowledge, the PCE of 9.53% is one of the highest values reported in literature to date for the non-fullerene PSCs. The results indicate that J61 is a promising medium bandgap polymer donor in non-fullerene PSCs.
To simultaneously achieve low photon energy loss (E loss) and broad spectral response, the molecular design of the wide band gap (WBG) donor polymer with a deep HOMO level is of critical importance ...in fullerene-free polymer solar cells (PSCs). Herein, we developed a new benzodithiophene unit, i.e., DTBDT-EF, and conducted systematic investigations on a WBG DTBDT-EF-based donor polymer, namely, PDTB-EF-T. Due to the synergistic electron-withdrawing effect of the fluorine atom and ester group, PDTB-EF-T exhibits a higher oxidation potential, i.e., a deeper HOMO level (ca. −5.5 eV) than most well-known donor polymers. Hence, a high open-circuit voltage of 0.90 V was obtained when paired with a fluorinated small molecule acceptor (IT-4F), corresponding to a low E loss of 0.62 eV. Furthermore, side-chain engineering demonstrated that subtle side-chain modulation of the ester greatly influences the aggregation effects and molecular packing of polymer PDTB-EF-T. With the benefits of the stronger interchain π–π interaction, the improved ordering structure, and thus the highest hole mobility, the most symmetric charge transport and reduced recombination are achieved for the linear decyl-substituted PDTB-EF-T (P2)-based PSCs, leading to the highest short-circuit current density and fill factor (FF). Due to the high Flory–Huggins interaction parameter (χ), surface-directed phase separation occurs in the P2:IT-4F blend, which is supported by X-ray photoemission spectroscopy results and cross-sectional transmission electron microscope images. By taking advantage of the vertical phase distribution of the P2:IT-4F blend, a high power conversion efficiency (PCE) of 14.2% with an outstanding FF of 0.76 was recorded for inverted devices. These results demonstrate the great potential of the DTBDT-EF unit for future organic photovoltaic applications.
There is an urgent need for low-cost, resource-friendly, high-energy-density cathode materials for lithium-ion batteries to satisfy the rapidly increasing need for electrical energy storage. To ...replace the nickel and cobalt, which are limited resources and are associated with safety problems, in current lithium-ion batteries, high-capacity cathodes based on manganese would be particularly desirable owing to the low cost and high abundance of the metal, and the intrinsic stability of the Mn4+ oxidation state. Here we present a strategy of combining high-valent cations and the partial substitution of fluorine for oxygen in a disordered-rocksalt structure to incorporate the reversible Mn2+/Mn4+ double redox couple into lithium-excess cathode materials. The lithium-rich cathodes thus produced have high capacity and energy density. The use of the Mn2+/Mn4+ redox reduces oxygen redox activity, thereby stabilizing the materials, and opens up new opportunities for the design of high-performance manganese-rich cathodes for advanced lithium-ion batteries.
We design and synthesize four fused-ring electron acceptors based on 6,6,12,12-tetrakis(4-hexylphenyl)-indacenobis(dithieno3,2-b;2′,3′-dthiophene) as the electron-rich unit and ...1,1-dicyanomethylene-3-indanones with 0–2 fluorine substituents as the electron-deficient units. These four molecules exhibit broad (550–850 nm) and strong absorption with high extinction coefficients of (2.1–2.5) × 105 M–1 cm–1. Fluorine substitution downshifts the LUMO energy level, red-shifts the absorption spectrum, and enhances electron mobility. The polymer solar cells based on the fluorinated electron acceptors exhibit power conversion efficiencies as high as 11.5%, much higher than that of their nonfluorinated counterpart (7.7%). We investigate the effects of the fluorine atom number and position on electronic properties, charge transport, film morphology, and photovoltaic properties.
The development of semiconducting polymers is imperative to improve the performance of polymer-based solar cells (PSCs). In this study, new semiconducting polymers based on ...naphtho1,2-c:5,6-c′bis1,2,5thiadiazole (NTz), PNTz4TF2 and PNTz4TF4, having 3,3′-difluoro-2,2′-bithiophene and 3,3′,4,4′-tetrafluoro-2,2′-bithiophene, respectively, are designed and synthesized. These polymers possess a deeper HOMO energy level than their counterpart, PNTz4T, which results in higher open-circuit voltages in solar cells. This concequently reduces the photon energy loss that is one of the most important issues surrounding PSCs. The PNTz4TF4 cell exhibits up to 6.5% power conversion efficiency (PCE), whereas the PNTz4TF2 cell demonstrates outstanding device performance with as high as 10.5% PCE, which is quite high for PSCs. We further discuss the performances of the PSCs based on these polymers by correlating the charge generation and recombination dynamics with the polymer structure and ordering structure. We believe that the results provide new insights into the design of semiconducting polymers and that there is still much room for improvement of PSC efficiency.
Biscuits are wheat flour-based manufactured food products. Another option is to locate a flour substitute, such as plantain flour or purple rice. This study aims to establish the ideal ratio of ...purple rice flour and plantain flour based on the quality attributes of biscuits. This study employed a one-factor, Completely Randomized Design (CRD) with five treatment levels and three replications. The observational data were analysed using ANOVA with the DNMRT further test at a 5% significant level. The treatment in this study compared purple rice flour and plantain flour to prepare biscuits. The ratio of purple rice flour to plantain flour had a very significant (p <0.01) effect on water content (3.56%), ash content (2.11%), fat content (25.18%), crude fiber content (17.85%), protein content (4.72%), and carbohydrate content (61.49%), but no significant effect (p >0.01) on antioxidant activity (55.83%). Except for protein, all treatments meet the SNI's requirements for biscuit quality. Based on the organoleptic test of taste, aroma, texture, and colour preferred by panellist with score of A (90-10) 3.52%, B (80-20) 3.97%, C (70-30) 4.42%, D (60-40) 5.03%, and E (50-50) 5.52% were obtained. The best-quality biscuits were in treatment E. (comparison of purple rice flour and plantain flour 50:50).
The radical fluoroalkylation of isocyanides with fluorinated sulfones is enabled by visible‐light photoredox catalysis. A wide range of readily available mono‐, di‐, and trifluoromethyl heteroaryl ...sulfones can thus be used as efficient radical fluoroalkylation reagents under mild conditions. This method not only describes a new synthetic application of fluorinated sulfones, but also provides a new route to fluoroalkyl radicals.
Sulfones in the spotlight: The radical fluoroalkylation of isocyanides with a wide range of readily available mono‐, di‐, and trifluoromethyl heteroaryl sulfones is enabled by visible‐light photoredox catalysis. Fluorinated sulfones can thus be used as precursors of fluoroalkyl radicals.
Background: Fluor albus is excessive fluid from vagina that is not menstruation. To reduce the symptoms of fluor albus, non-pharmacological treatment from the decoction water of red betel leaves ...(Piper crocantum) was used in the present study. These red betel leaves (Piper crocantum) contain alkaloids that the green betel leaves do not have, and the alkaloids play a role as an antimicrobial agent. Besides, the red betel leaves have antiseptic power that is twice higher than the green betel leaves. The red betel leaves (Piper crocantum) also contain carvakrol which is anti-fungal and disinfectant, and it that can be used as an antiseptic medicine to maintain oral cavity health, cure fluor albus disease, and alleviate bad odor. Purpose: The present study aims to discover the effectiveness of the decoction of red betel leaves in reducing the fluor albus symptoms. Method: This study uses quasi-experimental research design with one group undertaking pre- and post-tests. It involved 20 adolescent girls of Al-Adzkia Sentul Boarding School in which the sample was taken using purposive sampling techniques. Further, a closed ended questionnaire is used to collect data, then analyzed using paired t-test. Result: The results showed a meaningful difference before being given treatment for 13.40. After treatment the value became 8.27 with a p-value < of α (0.005). Conclusion: The results this study indicated a decrease in symptoms of vaginal discharge after the use of red betel leaf decoction and recommended it to be used as a form of non-pharmacological therapy or traditional medicine in reducing fluor albus symptoms in adolescent girls.
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