共查询到20条相似文献,搜索用时 11 毫秒
1.
Molecular Orientation: Simultaneous Edge‐on to Face‐on Reorientation and 1D Alignment of Small π‐Conjugated Molecules Using Room‐Temperature Mechanical Rubbing (Adv. Funct. Mater. 19/2018)
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jean‐Charles Ribierre Toshihiko Tanaka Li Zhao Yuki Yokota Shinya Matsumoto Daisuke Hashizume Kazuto Takaishi Tsuyoshi Muto Benoît Heinrich Stéphane Méry Fabrice Mathevet Toshinori Matsushima Masanobu Uchiyama Chihaya Adachi Tetsuya Aoyama 《Advanced functional materials》2018,28(19)
2.
π‐Conjugated Molecules Crosslinked Graphene‐Based Ultrathin Films and Their Tunable Performances in Organic Nanoelectronics
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xiaowei Ou Penglei Chen Lang Jiang Yunfan Shen Wenping Hu Minghua Liu 《Advanced functional materials》2014,24(4):543-554
Graphene‐based ultrathin films with tunable performances, controlled thickness, and high stability are crucial for their uses. The currently existing protocols, however, could hardly simultaneously meet these requirements. Using amino‐substituted π‐conjugated compounds, including 1,4‐diaminobenzene (DABNH2), benzidine (BZDNH2), and 5,10,15,20‐tetrakis (4‐aminophenyl)‐21H,23H‐porphine (TPPNH2), as cross‐linkages, a new protocol through which graphene oxide (GO) nanosheets can be anchored on solid supports with a high stability and controlled thickness via a layer‐by‐layer method is presented. A thermal annealing leads to the reduction of the films, and the qualities of the samples can be inherited by the as‐produced reduced GO films (RGO). When RGO films are integrated as source/drain electrodes in OFETs, tunable performances can be realized. The devices based on the BZDNH2‐crosslinked RGO electrodes exhibit similar electrical behaviors as those based on the non‐π‐conjugated compound crosslinked electrodes, while improved performances can be gained when those crosslinked by DABNH2 are used. The performances can be further improved when RGO films crosslinked by TPPNH2 are employed. This work likely paves a new avenue for graphene‐based films of tunable performances, controlled thickness, and high stability. 相似文献
3.
Kazi M. Alam Abhay P. Singh Ryan Starko‐Bowes Srikrishna C. Bodepudi Sandipan Pramanik 《Advanced functional materials》2012,22(15):3298-3306
π‐conjugated molecular organics such as rubrene, Alq3, fullerene, and PCBM have been used extensively over the last few decades in numerous organic electronic devices, including solar cells, thin‐film transistors, and large‐area, low‐cost flexible displays. Rubrene and Alq3, have emerged as promising platforms for spin‐based classical and quantum information processing, which has triggered significant research activity in the relatively new area of organic spintronics. Synthesis of these materials in a nanowire geometry, with feature sizes in the sub‐100 nm regime, is desirable as it often enhances device performance and is essential for development of high‐density molecular electronic devices. However, fabrication techniques that meet this stringent size constraint are still largely underdeveloped. Here, a novel, versatile, and reagentless method that enables growth of nanowire arrays of the above‐mentioned organics in the cylindrical nanopores of anodic aluminum oxide (AAO) templates is demonstrated. This method 1) allows synthesis of high‐density organic nanowire arrays on arbitrary substrates, 2) provides electrical access to the nanowire arrays, 3) offers tunability of the array geometry in a range overlapping with the relevant physical length scales of many organic devices, and 4) can potentially be extended to synthesize axially and radially heterostructured organic nanowires. Thus prepared nanowires are characterized extensively with an aim to identify their potential applications in diverse areas such as organic optoelectronics, photovoltaics, molecular nanoelectronics, and spintronics. 相似文献
4.
Difluorobenzothiadiazole‐Based Small‐Molecule Organic Solar Cells with 8.7% Efficiency by Tuning of π‐Conjugated Spacers and Solvent Vapor Annealing
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jin‐Liang Wang Fei Xiao Jun Yan Zhuo Wu Kai‐Kai Liu Zheng‐Feng Chang Ru‐Bo Zhang Hui Chen Hong‐Bin Wu Yong Cao 《Advanced functional materials》2016,26(11):1803-1812
The synthesis of a series of tetrafluorine‐substituted, wide‐bandgap, small molecules consisting of various π‐conjugated spacers (furan, thiophene, selenophene) between indacenodithiophene as the electron‐donating core and the electron‐deficient difluorobenzothiadiazole unit is reported and the effect of the π‐conjugated spacers on the photovoltaic properties is investigated. The alteration of the π‐conjugated spacer enables fine‐tuning of the photophysical properties and energy levels of the small molecules, and allows the adjustment of the charge‐transport properties, the morphology of the photoactive films, as well as their photovoltaic properties. Moreover, most of these devices exhibit superior device performances after CH2Cl2 solvent annealing than without annealing, with a high fill factor (0.70–0.75 for all cases). Notably, the devices based on the new molecule BIT4FTh (with thiophene as the spacer) show an outstanding PCE of 8.7% (with an impressive FF of 0.75), considering its wide‐bandgap (1.81 eV), which is among the highest efficiencies reported so far for small‐molecules‐based solar cells. The morphologies of the photoactive layers with/without CH2Cl2 solvent annealing are characterized by atomic force microscopy, transmission electron microscopy and two‐dimensional grazing incidence X‐ray diffraction analysis. The results reported here clearly indicate that highly efficient small‐molecules‐based solar cells can be achieved through rational design of their molecular structure and optimization of the phase‐separated morphology via an adapted solvent–vapor annealing process. 相似文献
5.
Ran Kim Paul S. K. Amegadze Il Kang Hui‐Jun Yun Yong‐Young Noh Soon‐Ki Kwon Yun‐Hi Kim 《Advanced functional materials》2013,23(46):5719-5727
A high‐performance naphthalene diimide (NDI)‐based conjugated polymer for use as the active layer of n‐channel organic field‐effect transistors (OFETs) is reported. The solution‐processable n‐channel polymer is systematically designed and synthesized with an alternating structure of long alkyl substituted‐NDI and thienylene–vinylene–thienylene units (PNDI‐TVT). The material has a well‐controlled molecular structure with an extended π‐conjugated backbone, with no increase in the LUMO level, achieving a high mobility and highly ambient stable n‐type OFET. The top‐gate, bottom‐contact device shows remarkably high electron charge‐carrier mobility of up to 1.8 cm2 V?1 s?1 (Ion/Ioff = 106) with the commonly used polymer dielectric, poly(methyl methacrylate) (PMMA). Moreover, PNDI‐TVT OFETs exhibit excellent air and operation stability. Such high device performance is attributed to improved π–π intermolecular interactions owing to the extended π‐conjugation, apart from the improved crystallinity and highly interdigitated lamellar structure caused by the extended π–π backbone and long alkyl groups. 相似文献
6.
Layer‐by‐Layer Conjugated Extension of a Semiconducting Polymer for High‐Performance Organic Field‐Effect Transistor
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mi Jang Se Hyun Kim Han‐Koo Lee Yun‐Hi Kim Hoichang Yang 《Advanced functional materials》2015,25(25):3833-3839
A donor–acceptor (D–A) semiconducting copolymer, PDPP‐TVT‐29, comprising a diketopyrrolopyrrole (DPP) derivative with long, linear, space‐separated alkyl side‐chains and thiophene vinylene thiophene (TVT) for organic field‐effect transistors (OFETs) can form highly π‐conjugated structures with an edge‐on molecular orientation in an as‐spun film. In particular, the layer‐like conjugated film morphologies can be developed via short‐term thermal annealing above 150 °C for 10 min. The strong intermolecular interaction, originating from the fused DPP and D–A interaction, leads to the spontaneous self‐assembly of polymer chains within close proximity (with π‐overlap distance of 3.55 Å) and forms unexpectedly long‐range π‐conjugation, which is favorable for both intra‐ and intermolecular charge transport. Unlike intergranular nanorods in the as‐spun film, well‐conjugated layers in the 200 °C‐annealed film can yield more efficient charge‐transport pathways. The granular morphology of the as‐spun PDPP‐TVT‐29 film produces a field‐effect mobility (μ FET) of 1.39 cm2 V?1 s?1 in an OFET based on a polymer‐treated SiO2 dielectric, while the 27‐Å‐step layered morphology in the 200 °C‐annealed films shows high μ FET values of up to 3.7 cm2 V?1 s?1. 相似文献
7.
Lu Yang Huisheng Peng Kun Huang Joel T. Mague Hexing Li Yunfeng Lu 《Advanced functional materials》2008,18(10):1526-1535
Hierarchical assemblies of perylenetetracarboxylic diimide bridged silsesquioxane (PDBS) with controlled structure at multi‐length scale are studied using both experimental and computational methods. The organization process spans multi‐length scales and includes three continuous steps: 1) stacking of the preprogrammed molecules into small clusters, 2) growing of the small clusters into nanoscale building blocks with various sizes and shapes depending on the experimental conditions, and 3) aggregation of nanoscale building blocks into micro‐ or macro‐scale assemblies. The main factors determining the assembly morphology are the second and third steps, which can be controlled by varying the experimental conditions, such as solution drying rate, solvent composition, and PDBS concentration. Despite the different morphologies, all of these assemblies possess highly ordered lamellar structure. It is found that incorporating perylenetetracarboxylic diimide (PD) moieties into the highly ordered silica network endows the PD components with high thermal and mechanical stability, as well as improved optical and electronic properties. 相似文献
8.
Michal Firstenberg Kammasandra Nanjunda Shivananda Irit Cohen Olga Solomeshch Vladislav Medvedev Nir Tessler Yoav Eichen 《Advanced functional materials》2011,21(4):634-643
Sequence‐independent or “click”‐type chemistry is applied for the preparation of novel π‐conjugated oligomers. A variety of bi‐functional monomers for Wittig–Horner olefination are developed and applied in a sequential protection–deprotection process for the preparation of structurally similar π‐conjugated oligomers. Selected oligomers are incorporated as the organic semiconductors in light‐emitting diodes and a field‐effect transistor, demonstrating the potential of the approach. 相似文献
9.
10.
Systematic Investigation of Side‐Chain Branching Position Effect on Electron Carrier Mobility in Conjugated Polymers
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jin‐Hu Dou Yu‐Qing Zheng Ting Lei Shi‐Ding Zhang Zhi Wang Wen‐Bin Zhang Jie‐Yu Wang Jian Pei 《Advanced functional materials》2014,24(40):6270-6278
Recently, polymer field‐effect transistors have gone through rapid development. Nevertheless, charge transport mechanism and structure‐property relationship are less understood. Here we use strong electron‐deficient benzodifurandione‐based poly(p‐phenylene vinylene) ( BDPPV ) as polymer backbone and develop six BDPPV ‐based polymers ( BDPPV‐C1 to C6 ) with various side‐chain branching positions to systematically study the side‐chain effect on device performance. All the polymers exhibited ambient‐stable n‐type transporting behaviors with the highest electron mobility of up to 1.40 cm2 V?1 s?1. The film morphologies and microstructures of all the six polymers were systematically investigated. Our results demonstrate that the interchain π–π stacking distance decreases as moving the branching position away from polymer backbones, and an unprecedentedly close π–π stacking distance down to 3.38 Å is obtained for BDPPV‐C4 to C6 . Nonetheless, closer π–π stacking distance does not always correlate with higher electron mobility. Polymer crystallinity, thin film disorder, and polymer packing conformation, which all influenced by side‐chain branching position, are proved to show significant influence on device performance. Our study not only reveals that π–π stacking distance is not the decisive factor on carrier mobility in conjugated polymers but also demonstrates that side‐chain branching position engineering is a powerful strategy to modulate and balance these factors in conjugated polymers. 相似文献
11.
Kammasandra Nanjunda Shivananda Irit Cohen Elena Borzin Yulia Gerchikov Michal Firstenberg Olga Solomeshch Nir Tessler Yoav Eichen 《Advanced functional materials》2012,22(7):1489-1501
Sequence‐independent or “click” chemistry is applied for the preparation of a series of novel and structurally similar π‐conjugated oligomers. The new oligomers are prepared using Wittig–Horner chemistry from bifunctional building blocks that can be interconnected to one another at any desired sequence. The bifunctional building blocks consist of aromatic skeletons with acetal protected aldehyde groups on one side and a phosphonic acid diethyl ester group para to the aldehyde functionality. The first step in the arylenevinylene formation is a Wittig–Horner coupling of a functionalized aldehyde with the methyl phosphonate ester ylide of a bifunctional monomer. A stepwise protection–deprotection process is applied for the preparation of structurally similar π‐conjugated oligo‐phenylene vinylenes. New di‐, tri‐, penta‐, and hepta‐phenylenevinylenes are prepared and characterized. Selected penta‐arylenevinylenes are incorporated as the semiconductor channel in organic field‐effect transistors. 相似文献
12.
Conjugated Polymers: Systematic Investigation of Side‐Chain Branching Position Effect on Electron Carrier Mobility in Conjugated Polymers (Adv. Funct. Mater. 40/2014)
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jin‐Hu Dou Yu‐Qing Zheng Ting Lei Shi‐Ding Zhang Zhi Wang Wen‐Bin Zhang Jie‐Yu Wang Jian Pei 《Advanced functional materials》2014,24(40):6404-6404
13.
Ehren M. Mannebach Josef W. Spalenka Phillip S. Johnson Zhonghou Cai F. J. Himpsel Paul G. Evans 《Advanced functional materials》2013,23(5):554-564
Monolayer‐thickness two‐dimensional layers of α,ω‐dihexylsexithiophene (α,ω‐DH6T) exhibit field‐effect hole mobility of up to 0.032 cm2 V?1 s?1, higher than previously reported for monolayers of other small‐molecule organic semiconductors. In situ measurements during deposition show that the source‐drain current saturates rapidly after the percolation of monolayer‐high islands, indicating that the electrical properties of α,ω‐DH6T transistors are largely determined by the first molecular monolayer. The α,ω‐DH6T monolayer consists of crystalline islands in which the long axes of molecules are oriented approximately perpendicular to the plane of the substrate surface. In‐plane lattice constants measured using synchrotron grazing‐incidence diffraction are larger in monolayer‐thickness films than the in‐plane lattice constants of several‐monolayer films and of previously reported thick‐film structures. Near‐edge X‐ray absorption fine structure spectroscopy (NEXAFS) reveals that the larger in‐plane lattice constant of single‐monolayer films arises from a larger tilt of the molecular axis away from the surface normal. NEXAFS spectra at the C 1s and S 2p edges are consistent with a high degree of molecular alignment and with the local symmetry imposed by the thiophene ring. The high mobility of holes in α,ω‐DH6T monolayers can be attributed to the reduction of hole scattering associated with the isolation of the thiophene core from the interface by terminal hexyl chains. 相似文献
14.
Ya Wang Youshen Wu Ke Li Shihong Shen Zeying Liu Daocheng Wu 《Advanced functional materials》2019,29(1)
Long blood circulation in vivo remains a challenge to dual‐drug‐loaded nanocarriers for synergistic chemotherapy. Herein, a novel strategy to prepare lollipop‐like dual‐drug‐loaded nanoparticles (DOX–PDA–gossypol NPs) is developed based on the self‐assembly of gossypol, doxorubicin (DOX), and polydopamine (PDA) via π–π stacking. Dopamine polymerizes to PDA and fills the gaps between the gossypol and DOX molecules to form the super compact long‐circulating nanoparticles. The DOX–PDA–gossypol NPs show a suitable particle size of 59.6 ± 9.6 nm, high drug loading of 91%, superb stability, high maximum‐tolerated dose (MTD) of over 60 mg kg‐1, and negligible toxicity. These NPs also exhibit pH‐dependent drug release and low combination index (0.23). Notably, they show dramatically ultralong blood circulation (>192 h) with elimination half times 458‐fold and 258‐fold longer than that of free DOX and free gossypol, respectively. These values are markedly higher than most of the reported results. Therefore, the DOX–PDA–gossypol NPs have a high tumor accumulation of 12% remaining on the 8th day postinjection. This characteristic contributes to the excellent tumor comprehensive synergistic therapeutic efficacy (TIR > 90%) with low administration dosage and is benefitted for widening the drug therapeutic window. Thus, the proposed strategy has remarkable potential for tumor synergistic therapy. 相似文献
15.
Suzhi Cai Huifang Shi Dan Tian Huili Ma Zhichao Cheng Qi Wu Mingxing Gu Ling Huang Zhongfu An Qian Peng Wei Huang 《Advanced functional materials》2018,28(9)
Efficient ultralong organic phosphorescent materials have potential applications in some fields, such as bioimaging, anti‐counterfeiting, and sensors. Nevertheless, phosphorescence efficiencies of metal‐free organic materials are low due to weak spin–orbit coupling and vigorous nonradiative transitions under ambient conditions. Here a chemical strategy to improve phosphorescence efficiency with intermolecular π‐type halogen bonding construction via isomerism is presented. X‐ray single crystal analysis reveals that different halogen bonding is formed among p‐BrTCz, m‐BrTCz, and o‐BrTCz crystals. Phosphorescence efficiency of m‐BrTCz in solid can reach 13.0%, seven times of o‐BrTCz in solid owing to effective π‐type halogen bonding, which is further confirmed by theoretical calculations. However, ultralong phosphorescence lifetimes are little affected, 155, 120, and 156 ms for p‐BrTCz, m‐BrTCz, and o‐BrTCz in the solid state, respectively. Furthermore, a simple pattern for data encryption and decryption is first demonstrated under sunlight. This result will provide an approach for improving the phosphorescent efficiency of metal‐free organic phosphors with ultralong luminescence. 相似文献
16.
Jia Guan Wei Chen Yafei Li Guangtao Yu Zhiming Shi Xuri Huang Chiachung Sun Zhongfang Chen 《Advanced functional materials》2013,23(12):1507-1518
Under first‐principles computations, a simple strategy is identified to modulate the electronic and magnetic properties of zigzag graphene nanoribbons (zGNRs). This strategy takes advantage of the effect of the floating dipole field attached to zGNRs via π–π interactions. This dipole field is induced by the acceptor/donor functional groups, which decorate the ladder‐structure polydiacetylene derivatives with an excellent delocalized π‐conjugated backbone. By tuning the acceptor/donor groups, –C≡C– number, and zGNR width, greatly enriched electronic and magnetic properties, e.g., spin gapless semiconducting, half‐metallic, and metallic behaviors, with the antiferromagnetic?ferromagnetic conversion can be achieved in zGNRs with perfect, 57‐reconstructed, and partially hydrogenated edge patterns. 相似文献
17.
Yemineni S. L. V. Narayana Supratim Basak Martin Baumgarten Klaus Müllen Rajadurai Chandrasekar 《Advanced functional materials》2013,23(47):5875-5880
The synthesis of two cyan color (blue and green emission) displaying high molecular weight 2,6‐bis(pyrazolyl)pyridine‐co‐octylated phenylethynyl conjugated polymers (CPs) is presented. The conjugated polymers are solution‐processed to prepare spin coated thin films and self‐assembled nano/microscale spheres, exhibiting cyan color under UV. Additionally, the metal coordinating ability of the 2,6‐bis(pyrazolyl)pyridine available on the surface of the CP films and spheres is exploited to prepare red emitting Eu(III) metal ion containing conjugated polymer (MCCP) layer. The fabricated hybrid (CP/MCCP) films and spheres exhibit bright white‐light under UV exposure. The Commission Internationale de l'Eclairage (CIE) coordinates are found to be (x = 0.33, y = 0.37) for hybrid films and (x = 0.30, y = 0.35) for hybrid spheres. These values are almost close to the designated CIE coordinates for ideal white‐light color (x = 0.33, y = 0.33). This easy and efficient fabrication technique to generate white‐color displaying films and nano/microspheres signify an important method in bottom‐up nanotechnology of conjugated polymer based hybrid solid state assemblies. 相似文献
18.
Design,Synthesis, and Versatile Processing of Indolo[3,2‐b]indole‐Based π‐Conjugated Molecules for High‐Performance Organic Field‐Effect Transistors
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Illhun Cho Sang Kyu Park Boseok Kang Jong Won Chung Jin Hong Kim Kilwon Cho Soo Young Park 《Advanced functional materials》2016,26(17):2966-2973
A series of indolo[3,2‐b]indole (IDID) derivatives comprising the core unit of N,N‐dihexyl‐IDID with different aromatic and aliphatic substituents at 2‐ and 7‐position are designed and synthesized to construct high‐performance organic semiconductors by different processing routes. Structure‐property relationship of the derivatives is comprehensively studied in terms of their photophysical, electrochemical, structural, and electrical characteristics. IDID derivatives are either evaporated in vacuum or dissolved in common organic solvents to ensure applicalbility in different processing routes toward outstanding p‐type semiconductor films. Among others, the excellently soluble compound 4H4TIDID (with 2‐ and 7‐substituents of 5‐hexyl‐2,2′‐bithiophene moiety, solubility >20 wt% in chloroform), shows the highest field‐effect hole mobility of 0.97 cm2 V?1 s?1 in a device constructed by vacuum‐deposition and 0.18 cm2 V?1 s?1 in device cosntructed by spin‐coating, respectively. The 2D grazing incidence X‐ray diffraction of 4H4TIDID films in both devices identically show the 2D molecular orientation favorable for the high transistor mobility. 相似文献
19.
Controlled Assembly of Poly(3‐hexylthiophene): Managing the Disorder to Order Transition on the Nano‐ through Meso‐Scales
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Self‐assembly of conjugated organic semiconductors into ordered, larger scale entities is a critical process to achieve efficient charge transport at the nano‐ through macro‐scales, and various methodologies aimed at enhancing molecular ordering have been introduced. However, mechanistic understanding is limited. Here, a mechanistic elucidation of poly(3‐hexylthiophene) (P3HT) molecular self‐assembly is proposed based on experimental demonstration of controlled, solution‐based P3HT self‐assembly into rod‐like polycrystalline nanostructures. The synergistic combination of nonsolvent addition and ultrasonication facilitates rod‐like P3HT nanostructure formation in solution. Importantly, through sequential application of both treatments, nanostructure length can be easily modulated, and the assembly process is shown to follow a simple 2‐step crystallization model, which depends upon nucleation followed by growth. Through arrays of experimental results, the validity of 2‐step crystallization is confirmed and is proposed as a comprehensive platform to understand self‐assembly processes of conjugated polymers into larger, ordered mesoscale entities. 相似文献
20.
Jia Guan Wei Chen Yafei Li Guangtao Yu Zhiming Shi Xuri Huang Chiachung Sun Zhongfang Chen 《Advanced functional materials》2013,23(12):1478-1478