Proses Produksi Dan Pengemasan Yoghurtdicv. Cita Nasional Salatiga

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5,6-Difluorobenzothiazole-Based Conjugated Polymers with Large Band Gaps and Deep Highest Occupied Molecular Orbital Levels

A 5,6-difluorobenzothiazole-based dibromo monomer was successfully synthesized, from which new fluorinated conjugated polymers PF-ffBTz and PFN-ffBTz were prepared via copolymerizations with two fluorene-based diboronic ester monomers. Twisted fluorene-ffBTz backbones enable PF-ffBTz and PFN-ffBTz with large band gaps up to 3.10 eV and deep-lying highest occupied molecular orbital levels down to −6.2 eV. The chemical structures of PF-ffBTz and PFN-ffBTz impart some new functionalities of fluorinated conjugated polymers. PF-ffBTz can show deep blue electroluminescent emission, with high external quantum efficiency of 3.71%. PFN-ffBTz, with amino-functionalized side chains on the fluorene unit, can serve as an efficient cathode interlayer in inverted polymer solar cells (PSCs), showing better photovoltaic performances if compared with a ZnO interlayer. In addition, it is found that using an optical filter to cut off the short wavelength section (≤380 nm) of incident light can significantly elevate photostability of PSCs under continuous illumination

Siloxane-Terminated Side Chain Engineering of Acceptor Polymers Leading to Over 7% Power Conversion Efficiencies in All-Polymer Solar Cells

To investigate the influence of functional pendent groups on acceptor polymers and photovoltaic properties of all-polymer solar cells (all-PSCs), two novel acceptor polymers containing siloxane-terminated side chains are synthesized and characterized. Increasing the content of siloxane-terminated side chains can reduce π–π stacking distance and improve crystalline behavior, yet lead to poorer solubility of the acceptor polymers. By modulating the proper loadings of siloxane-terminated side chains on the acceptor polymers, the PBDB-T:PNDI-Si25 all-PSC attains a maximal power conversion efficiency (PCE) of 7.4% with an outstanding fill factor of 0.68. The results provide new insights for developing high-performance all-PSCs through functional group engineering on the acceptor polymers, to achieve good solubility, polymer miscibility, and blend morphology

High Efficiency and High <i>V</i>_oc Inverted Polymer Solar Cells Based on a Low-Lying HOMO Polycarbazole Donor and a Hydrophilic Polycarbazole Interlayer on ITO Cathode

In this work, poly­[<i>N</i>-9′-heptadecanyl-2,7-carbazole-<i>alt</i>-5,5-(4,7-di-2-thienyl-5,6-bis­(dodecyloxy)-2,1,3-benzothiadiazole)] (PCDTBT12) was synthesized as the polymer donor for photovoltaic application. PCDTBT12 possesses a band gap of 1.99 eV, a low-lying HOMO of −5.6 eV, and good hole mobility up to 4.1 × 10^–3 cm² V^–1 s^–1. With ZnO as the interlayer on an ITO cathode, a PCDTBT12-based inverted solar cell showed a high open-circuit voltage of 0.98 V and a good power conversion efficiency (PCE) of 5.53%, suggesting that PCDTBT12 would be a promising donor material in the fabrication of a subcell for shorter wavelength absorption in a tandem solar cell. Using PC-P, a homopolymer of 2,7-carbazole with hydrophilic phosphonate side chains, as an interlayer polymer on the ITO cathode could further elevate the efficiency to 6.04% because of increased current (higher efficiency of 6.2% was achieved for a smaller cell area of 0.045 cm²). The efficiencies are the highest ones so far reported for an inverted solar cell with an organic cathode interlayer. It was proposed that the hydrophilic side chains of PC-P supplied a subgap state for electron transport. The two devices showed comparable air stability, and retained over 96% of their initial PCEs after storage in air for more than 1 month. Therefore, a hydrophilic conjugated polymer as the cathode interlayer, already shown in outstanding cathode modifications in conventional polymer solar cells, will play an important role in the future development of high efficiency and air-stable inverted solar cells

Quantum Mechanical Prediction and Experimental Verification of Au(I)-Catalyzed Substitution-Controlled Syntheses of 1<i>H</i>‑Pyrido[4,3‑<i>b</i>]indole and Spiro[indoline-3,3′-pyridine] Derivatives

Density functional theory calculations were applied to predict the pathways of gold(I)-catalyzed cycloisomerization of the indole substrates with 1,6-enynes, which were consistent with the ensuing experimental results. The substitution-controlled synthesis led to the formation of 1H-pyrido[4,3-b]indole and spiro[indoline-3,3′-pyridine] derivatives in a tunable way. The reactions had good functional group tolerances, and a possible mechanism was proposed based on the computational and experimental results

A Highly Crystalline Wide-Band-Gap Conjugated Polymer toward High-Performance As-Cast Nonfullerene Polymer Solar Cells

A new wide-band-gap conjugated polymer PBODT was successfully synthesized that showed high crystallinity and was utilized as the active material in nonfullerene bulk-heterojunction polymer solar cells (PSCs). The photovoltaic devices based on the as-cast blend films of PBODT with ITIC and IDIC acceptors showed notable power conversion efficiencies (PCEs) of 7.06% and 9.09%, with high open-circuit voltages of 1.00 and 0.93 V that correspond to low energy losses of 0.59 and 0.69 eV, respectively. In the case of PBODT:ITIC, lower exciton quenching efficiency and monomolecular recombination are found for devices with small driving force. On the other hand, the relatively higher driving force and suppressed monomolecular recombination for PBODT:IDIC devices are identified to be the reason for their higher short-circuit current density (<i>J</i>_sc) and higher PCEs. In addition, when processed with the nonchlorinated solvent 1,2,4-trimethylbenzene, a good PCE of 8.19% was still achieved for the IDIC-based device. Our work shows that such wide-band-gap polymers have great potential for the environmentally friendly fabrication of highly efficient PSCs