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Journal of Energy Chemistry 2019年第8期28卷 138-143,I0006页

作者： Yuan Guo Guangchao Han yuanping yi Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids CAS Research/Education Center for Excellence in Molecular Sciences Institute of Chemistry Chinese Academy of SciencesBeijing 100190 China University of Chinese Academy Sciences Beijing 100049 China

Side chains play a critical role in tuning intermolecular interaction and charge transport in organic semiconductors. Here, we have systematically investigated the impact of branching positions of the alkyl side chains on the molecular packing and electron transport properties of a series of bay-linked dimeric perylenediimide(PDI) derivatives by atomistic molecular dynamics simulations in combination with charge transfer rate theory and kinetic Monte Carlo simulations. The results show that despite of different branching positions of the alkyl chains,π–π stacking is effectively inhibited for all the dimeric PDI derivatives. As the branching position moves away from the PDI backbone, the appearance of the alkyl atoms around the PDI backbone will first decrease and then increase. Correspondingly, the short contacts between the PDI moieties are first enhanced and then reduced. In particular, when the branching position is at the third carbon atom, the intermolecular connectivity becomes the most effective and the electron mobility is significantly increased by 2 times.

关键词： Molecular packing Electron mobility Branching position Perylenediimide

Electronic polarization in dipolar organic molecular semiconductors:The case study of 1,2,3,4-tetrafluoro-6,7-dimethylnaphthalene crystal

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Chinese Chemical Letters 2020年第3期31卷 797-800页

作者： Xiaoyi Ma yuanping yi Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic SolidsCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy Sciences Beijing 100049China

Electronic polarization has an important impact on the site energies of charge carriers that play a key role in determining the charge transport in organic *** molecules have strong intermolecular interactions and widespread applications in organic *** r,compared with nonpolar organic semiconductors,electronic polarization for dipolar systems has been rarely ***,taking 1,2,3,4-tetrafluoro-6,7-dimethylnaphthalene as representative,we have calculated the electronic polarization energies of dipolar organic molecular crystals by means of a polarizable forcefield ***,our results point to that the polarization energies for this dipolar system are similar to those of nonpolar *** addition,theπ-πstack contributes only about 30%~40%to the total polarization energy,thus the polarization effects along the three dimensions should be treated equally even for the one-dimensional stacking crystals.

关键词： Electronic polarization Dipolar Organic semiconductors Charge transport Polarizable force field

The critical role of energetic fluctuations in charge separation for efficient molecular doping of organic semiconductors

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Science China Chemistry 2024年第11期67卷 3675-3680页

作者： Yan Zeng Guangchao Han yuanping yi Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Molecular doping is essential to improve the electrical conductivity of organic semiconductors for high-performance organic electronic devices. However, the doping efficiency is influenced by several factors, such as the energy levels, energetic fluctuations, dielectric properties, and molecular packing structures of the doped films, and the underlying mechanisms for highefficiency doping are still unclear. Here, through multi-level theoretical simulations on a series of fullerene derivatives, we identify that the energetic fluctuations can play a decisive role in activating charge separation for molecular doping. In particular,the doping efficiency appears to be exponentially increased with the fluctuation of charge polarization energies. Therefore,although the charge mobility is somewhat decreased, the experimental electrical conductivity is improved with the increased energetic fluctuation. Moreover, it has been found that polarization energy fluctuation can be effectively enhanced by simply introducing side chains with greater flexibility into organic semiconductors. This article paves the way towards high-efficiency molecular doping of organic semiconductors.

关键词： doping efficiency polarization energies energetic fluctuations organic semiconductors

Y6 and its derivatives: molecular design and physical mechanism

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National Science Review 2021年第8期8卷 9-11页

作者： Qingya Wei Jun Yuan yuanping yi Chunfeng Zhang yingping Zou College of Chemistry and Chemical Engineering Central South University Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of ChemistryChinese Academy of Sciences National Laboratory of Solid State Microstructures School of Physics and Collaborative Innovation Center for Advanced Microstructures Nanjing University

Non-fullerene-acceptor(NFA) materials in the bulk heterojunction(BHJ) play an important role in high-performance organic solar cells(OSCs). Recently,Y-series acceptors with an A-DA D-A structure have been a research hotspot and advanced device efficiency to 15%–18%. This perspective will focus on the discovery of Y6 and its derivatives as well as the intrinsic physical mechanism of Y-series-based devices, which provides a guideline for future molecular design.

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Regulation of excitation transit ons by molecular design endowing full-color-tunable emissions with unexpected high quantum yields for bioimaging application

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Science China Chemistry 2018年第4期61卷 418-426页

作者： Feng Liu Shengliang Li Ruihong Duan Shuhai Qiu yuanping yi Shu Wang Xiaozhang Zhu Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Organic fluorophores are indispensible in chemical/biological imaging. The conjugated fluorescent molecules simultaneously possessing highly tunable emission, high quantum yield in solvents of different polarities, and large Stokes shift are quite rare. Herein, we report a new category of fluorophores based on diarylated thieno[3,4-b]thiophenes efficiently synthesized by direct C-H arylation reaction. TbT-Fluors showed full-color-tunable emissions with large Stokes shifts. Intriguingly,the fluorescence quantum yields of TbT-Fluors are barely sensitive to solvent polarities, approaching 100%. Based on photophysical and theoretical investigations, we found that the enhanced oscillator strength of the S_1-S_0 transition and increased T2-S1 energy difference can sufficiently compensate the negative effect from the decreased energy gap and increased reorganization energy in dimethyl sulfoxide(DMSO). Bioimaging applications revealed that some TbT-Fluors can penetrate the cell membrane and are superior for imaging in terms of high photochemical stability and low cytotoxicity. Furthermore, TbT-PhF exhibits specific colocalization with mitochondria in living cells.

关键词： donor-aeceptors systems dyes thieno[3 4-b]thiophene fluorescence bioimaging

Electronic, optical, and charge transport properties of A-π-A electron acceptors for organic solar cells: Impact of anti-aromatic π structures

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Chinese Chemical Letters 2019年第1期30卷 211-216页

作者： Yan Zeng Ruihong Duan Yuan Guo Guangchao Han Qingxu Li yuanping yi School of Science Chongqing University of Posts and Telecommunications CAS Key Laboratory of Organic Solids CAS Research/Education Center for Excellence in Molecular Sciences Institute of Chemistry Chinese Academy of Sciences

Organic solar cells based on acceptor-p-acceptor(A-π-A) electron acceptors have attracted intensive attention due to their increasing and record power conversion efficiencies. To date, almost all of the reported A-π-A electron acceptors are based on aromatic p structures. Here, we have investigated the impact of anti-aromatization of the p-bridges on the optoelectronic properties of A-π-A electron acceptors by(time-dependent) density functional theory. Our calculations show that besides the frontier molecular orbitals corresponding to the aromatic p-bridge based acceptors("aromatic" acceptors),additional and unique occupied and unoccupied frontier orbitals are found for the acceptors based on the anti-aromatic p-bridges("anti-aromatic" acceptors). Moreover, by tuning isomeric structures of the p-bridges(e.g., fusion orientations or linking positions of thiophene moieties), the optical excitation energies for the transition between the additional occupied and unoccupied levels turn to be close to or substantially lower with respect to those for the transition between the "aromatic" frontier orbitals. The optical absorption of the "anti-aromatic" acceptors is thus either stronger or broader than the "aromatic"acceptors. Finally, the reorganization energies for electron transport are tunable and dependent on the p-bridge structures. These results indicate a great potential of "anti-aromatic" electron acceptors in organic photovoltaics.

关键词： A-π-A electron acceptor Anti-aromatic structure Strong absorption Reorganization energy Organic solar cells

Heteroatom substitution-induced asymmetric A–D–A type non-fullerene acceptor for efficient organic solar cells

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Journal of Energy Chemistry 2020年第1期29卷 144-150,I0006页

作者： Chao Lia Jiali Song Yunhao Cai Guangchao Han Wenyu Zheng yuanping yi Hwa Sook Ryu Han Young Woo Yanming Sun School of Chemistry Beihang UniversityBeijing 100191China Beijing National Laboratory for Molecular Science Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China Department of Chemistry College of ScienceKorea UniversitySeoul 136-713Republic of Korea

Research on asymmetric A–D–A structured non-fullerene acceptors has lagged far behind the development of symmetric *** this contribution,by simply replacing one sulfur atom in indacenodithiophene unit with a selenium atom,an asymmetric building block Se PT and a corresponding asymmetric non-fullerene acceptor Se PT-IN have been *** Se PT-IN achieved a high efficiency of 10.20% in organic solar cells when blended with PBT1-C,much higher than that of symmetric TPT-IN counterpart(8.91%).Our results demonstrated an effective heteroatom substitution strategy to develop asymmetric A–D–A structured non-fullerene acceptors.

关键词： Asymmetric non-fullerene acceptors Heteroatom substitution Organic solar cells Power conversion efficiency

Theoretical description of the geometric and electronic structures of organic-organic interfaces in organic solar cells: a brief review

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Science China Chemistry 2014年第10期57卷 1330-1339页

作者： FU Yao-Tsung yi yuanping COROPCEANU Veaceslav RISKO Chad AZIZ Saadullah G. BRDAS Jean-Luc School of Chemistry & Biochemistry and Center for Organic Photonics and Electronics Georgia Institute of Technology Key Laboratory of Organic Solids Beijing National Laboratory for Molecular Sciences (BNLMS) Institute of Chemistry Chinese Academy of Sciences Department of Chemistry King Abdulaziz University

We review some of the computational methodologies used in our research group to develop a better understanding of the geometric and electronic structures of organic-organic interfaces present in the active layer of organic solar cells. We focus in particular on the exciton-dissociation and charge-transfer processes at the pentacene-fullerene interface. We also discuss the local morphology at this interface on the basis of molecular dynamics simulations.

关键词： organic photovoltaics organic-organic interface multi-scale simulations

Design of antibacterial peptide-like conjugated molecule with broad spectrum antimicrobial ability

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Science China Chemistry 2018年第1期61卷 113-117页

作者： Hui Chen Meng Li Zhang Liu Rong Hu Shengliang Li Yuan Guo Fengting Lv Libing Liu yilin Wang yuanping yi Shu Wang Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Key Laboratory of Colloid Interface and Chemical Thermodynamics Institute of ChemistryChinese Academy of Sciences

Increasing multidrug-resistant （MDR） superbugs emerge worldwide causing a public health crisis. Consequently, it is urgent to find new antibiotics with efficient broad-spectrum antimicrobial activity. By virtue of versatility in molecular design, a new peptide-like cell membrane-broken molecule, oligo-（7,7＇-bifluoren-benzo[c][1,2,5]thiadiazole）（OFBT） possessing a conjugated backbone and eight pendant guanidyl moieties was designed and synthesized. OFBT exhibits favorable broad-spectrum of antirnicrobial activity to pathogens including Gram-negative and Gram-positive bacteria, and fungi with the minimum inhibitory concentration （MIC） below 3.0 μM. Moreover, OFBT exhibits high selectivity for pathogens over human cells to make it a promising broad spectrum antimicrobial agent.

关键词： OFBT broad spectrum antimicrobial activity

Electronic Polarization in an Organic π-π Stacking Crystal

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Electronic Polarization in an Organic π-π Stacking Crystal