Co-reporter:Lukasz Janasz, Marzena Gradzka, Dorota Chlebosz, Wojciech Zajaczkowski, Tomasz Marszalek, Adam Kiersnowski, Jacek Ulanski, and Wojciech Pisula
Langmuir May 2, 2017 Volume 33(Issue 17) pp:4189-4189
Publication Date(Web):April 6, 2017
DOI:10.1021/acs.langmuir.7b00563
Since the interfacial order of conjugated polymers plays an essential role for the performance of field-effect transistors, comprehensive understanding on the charge carrier transport in ultrathin semiconducting films below thicknesses of 10 nm is required for the development of transparent and flexible organic electronics. In this study, ultrathin films based on poly(3-hexylthiophene) as conjugated polymer model system with a thickness range from single monolayer up to several multilayers are investigated in terms of microstructure evolution and electrical properties of different molecular weights. Interestingly, a characteristic leap in field-effect mobility is observed for films with thickness greater than four layers. This threshold mobility regarding film thickness is attributed to the transition from 2D to 3D charge carrier transport along with an increased size of the P3HT aggregates in the upper layers of the film. These results disclose key aspects on the role of the film interlayer on the charge carrier transport through conjugated polymers in transistors.
Co-reporter:Lukasz Janasz, Adam Luczak, Tomasz Marszalek, Bertrand G. R. Dupont, Jaroslaw Jung, Jacek Ulanski, and Wojciech Pisula
ACS Applied Materials & Interfaces June 21, 2017 Volume 9(Issue 24) pp:20696-20696
Publication Date(Web):May 31, 2017
DOI:10.1021/acsami.7b03399
Ambipolar organic field-effect transistors (OFETs) based on heterojunction active films still suffer from an imbalance in the transport of electrons and holes. This problem is related to an uncontrolled phase separation between the donor and acceptor organic semiconductors in the thin films. In this work, we have developed a concept to improve the phase separation in heterojunction transistors to enhance their ambipolar performance. This concept is based on preaggregation of the donor polymer, in this case poly(3-hexylthiophene) (P3HT), before solution mixing with the small-molecular-weight acceptor, phenyl-C61-butyric acid methyl ester (PCBM). The resulting heterojunction transistor morphology consists of self-assembled P3HT fibers embedded in a PCBM matrix, ensuring balanced mobilities reaching 0.01 cm2/V s for both holes and electrons. These are the highest mobility values reported so far for ambipolar OFETs based on P3HT/PCBM blends. Preaggregation of the conjugated polymer before fabricating binary blends can be regarded as a general concept for a wider range of semiconducting systems applicable in organic electronic devices.Keywords: ambipolar charge carrier transport; heterojunction films; organic field-effect transistors; poly(3-hexylothipohene); [6,6]-phenyl-C61-butyric acid methyl ester;
Co-reporter:Wojciech Zajaczkowski;Shivananda Kammasandra Nanajunda;Yoav Eichen
RSC Advances (2011-Present) 2017 vol. 7(Issue 3) pp:1664-1670
Publication Date(Web):2017/01/04
DOI:10.1039/C6RA24740G
The interplay between the molecular structure, position and type of alkyl substituents on morphology and molecular packing is essential for the development of high-performance solution-processable organic semiconductors. This study focuses on the influence of the position and geometry of alkyl side chains on the supramolecular organization of thiophene- and dioxine-based oligomers. The structural investigation is performed by X-ray scattering for bulk and thin film samples. It is shown that attaching the side chains at the lateral position of the rigid oligomers mainly results in the formation of one-dimensional stacks. On the other hand, terminal alkyl substitution increases the steric hindrance between side chains and reduces the molecular interactions lowering the sample crystallinity.
Co-reporter:Mengmeng Li;Cunbin An;Tomasz Marszalek;Martin Baumgarten;Klaus Müllen
Advanced Materials 2016 Volume 28( Issue 11) pp:2245-2252
Publication Date(Web):
DOI:10.1002/adma.201503552
Co-reporter:Romain Stalder, Sreenivasa Reddy Puniredd, Michael Ryan Hansen, Unsal Koldemir, Caroline Grand, Wojciech Zajaczkowski, Klaus Müllen, Wojciech Pisula, and John R. Reynolds
Chemistry of Materials 2016 Volume 28(Issue 5) pp:1286
Publication Date(Web):February 17, 2016
DOI:10.1021/acs.chemmater.5b03968
A series of donor–acceptor isoindigo (iI)-based copolymers synthesized with increasing numbers of thiophene rings in the repeat unit (from zero to three thiophene rings, including silole and germole-bridged fused bithiophene units) is applied toward solution-processed OFET devices. Differential pulse voltammetry on thin films of the polymers recorded LUMO energy levels confined within a 0.1 eV range around 3.9 eV, while their bandgaps are estimated at 1.5 to 1.7 eV. The interchain π-stacking distance of each sample was evaluated from the 2D-WAXS diffraction patterns of annealed extruded filaments and the GIWAXS patterns of thin films, and were found to be all in the same range, between 3.65 and 3.75 Å for the thin films. Both p-type and n-type charge transport in thin film bottom gate, bottom contact transistor devices were recorded. In particular, the copolymer P(T-iI) containing one thiophene ring afforded well-balanced ambipolar p-type and n-type mobilities of 0.04 cm2/(V s) and 0.1 cm2/(V s), respectively. Under our processing conditions, the charge transport properties evolved from exclusively n-type to solely p-type as the number of thiophene rings within the repeat unit is increased to three rings in the case of P(T3-iI). This was observed despite all polymers displaying similar LUMO energy levels, interchain π-stacking distances, and microscopic thin film morphology (all face-on arrangement on the dielectric surface). This prompted a molecular-scale morphological analysis of P(T-iI) and P(T3-iI) in particular, using solid-state NMR spectroscopy in order to further investigate the stark difference in n-type mobilities between these two polymers. Using the complete assignment of solution 2D-NMR spectra of a thiophene-iI-thiophene model compound as guideline, the analysis of proton–carbon correlations in the solid-state 2D 13C{1H} FSLG-HETCOR NMR spectra of P(T-iI) and P(T3-iI) revealed differences in the molecular environment surrounding each iI unit. The latter suggests a stronger correlation of neighboring iI units in P(T-iI), whereas a stronger intermixing of iI and thiophenes prevails in P(T3-iI). We conclude that, in this study, the choice of the donor unit length within the primary structure of the D–A polymer can be responsible for hindering its n-type character.
Co-reporter:Mengmeng Li, Felix Hinkel, Klaus Müllen and Wojciech Pisula
Nanoscale 2016 vol. 8(Issue 17) pp:9211-9216
Publication Date(Web):30 Mar 2016
DOI:10.1039/C6NR01082B
In recent years organic field-effect transistors have received extensive attention, however, it is still a great challenge to fabricate monolayer-based devices of conjugated polymers. In this study, one single layer of poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene) is directly dip-coated, and its self-assembly is precisely tuned from nanofibers to granular aggregates by controlling the dielectric roughness on a sub-nanometer scale. The charge carrier transport of the monolayer transistor exhibits a strong dependence on the dielectric roughness, which is attributed to the roughness-induced effects of higher densities of grain boundaries and charge trapping sites as well as surface scattering. These results mark a great advance in the bottom-up fabrication of organic electronics.
Co-reporter:Mengmeng Li, Tomasz Marszalek, Klaus Müllen, and Wojciech Pisula
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 25) pp:16200-16206
Publication Date(Web):June 9, 2016
DOI:10.1021/acsami.6b03233
The effect of dielectric roughness on the microstructure evolution of thermally evaporated α,ω-dihexylsexithiophene (α,ω-DH6T) thin films from a single molecular layer to tens of monolayers (ML) is studied. Thereby, the surface roughness of dielectrics is controlled within a sub-nanometer range. It is found that the grain size of an α,ω-DH6T ML is affected by dielectric roughness, especially for 1.5 ML, whereby the transistor performance is barely influenced. This can be attributed to a domain interconnection in the second layer over a long-range formed on the rough surface. With deposition of more layers, both microstructure and charge carrier transport exhibit a roughness-independent behavior. The structural characterization of α,ω-DH6T 10 ML by grazing-incidence wide-angle X-ray scattering reveals that the interlayer distance is slightly decreased from 3.30 to 3.15 nm due to a higher roughness, while an unchanged π-stacking distance is in excellent agreement with the roughness-independent hole mobility. This study excludes the influence of molecular-solvent interaction and preaggregation taking place during solution deposition, and provides further evidence that the microstructure of the interfacial layer of organic semiconductors has only minor impact on the bulk charge carrier transport in thicker films.
Co-reporter:Mengmeng Li, Tomasz Marszalek, Yiran Zheng, Ingo Lieberwirth, Klaus Müllen, and Wojciech Pisula
ACS Nano 2016 Volume 10(Issue 4) pp:4268
Publication Date(Web):March 9, 2016
DOI:10.1021/acsnano.5b07742
A single molecular layer (monolayer) of organic semiconductors is proven to be sufficient to create a conducting channel for charge carriers in field-effect transistors, which is an ideal platform to investigate the correlation between molecular self-assembly and device performance. Herein, ultrathin films including mono- and bilayers of an n-type dicyanoperylene (PDI8-CN2) are solution-processed by dip-coating. The domain size of the polycrystalline layers is modulated via the surface roughness of the dielectric within an extremely narrow window from 0.15 to 0.39 nm. When the surface roughness is varied from smooth to rough, the domain size and molecular order in the monolayer are significantly decreased, leading to the reduction in electron mobility by 3 orders of magnitude. On the contrary, a lower roughness dependence is observed in the case of the bilayers, with only a slight difference in domain size and charge carrier transport. On the smooth surface, the bilayers exhibit a transistor performance identical to that of the bulk film, confirming that the first few layers near the dielectric dominate the charge carrier transport. Additionally, these results provide insights into the intrinsic role of the interfacial microstructure of small molecular organic semiconductors.Keywords: charge carrier transport; dielectric surface roughness; organic field-effect transistors; self-assembly; solution processing
Co-reporter:Yi Liu;Dr. Tomasz Marszalek;Dr. Klaus Müllen;Dr. Wojciech Pisula;Dr. Xinliang Feng
Chemistry – An Asian Journal 2016 Volume 11( Issue 15) pp:2107-2112
Publication Date(Web):
DOI:10.1002/asia.201600753
Abstract
A series of trisbenzothieno[1,2:7,8:13,14]hexa-peri-hexabenzocoronenes were synthesized and characterized by a combination of NMR, 2D NMR, MALDI-TOF MS, UV/Vis absorption spectroscopy, and 2D-WAXS measurement. By structural modulation like decoration of electro-donating alkoxyl chain, and conversion from an electron-rich thiophene ring into an electron-poor thiophene-S,S-dioxide moiety, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of the hexabenzocoronenes derivatives can be effectively tuned which is further verified by the DFT calculations and cyclic voltammetry.
Co-reporter:Mengmeng Li, Cunbin An, Tomasz Marszalek, Xin Guo, Yun-Ze Long, Hongxing Yin, Changzhi Gu, Martin Baumgarten, Wojciech Pisula, and Klaus Müllen
Chemistry of Materials 2015 Volume 27(Issue 6) pp:2218
Publication Date(Web):March 5, 2015
DOI:10.1021/acs.chemmater.5b00341
A novel donor–acceptor polymer, PPhTQ, is synthesized by condensing a phenanthrene unit onto a thiadiazoloquinoxaline moiety. This polymer shows a broad absorption band from visible to near-infrared and a very low optical bandgap of 0.80 eV. A well-balanced ambipolar field-effect behavior is observed for PPhTQ, with mobilities of 0.09 cm2 V–1 s–1 for holes and 0.06 cm2 V–1 s–1 for electrons. A two-dimensional charge carrier transport in the film is determined by low-temperature resistance measurements, and an ordered molecular organization mainly in a face-on fashion is found by grazing incidence wide-angle X-ray scattering. More importantly, a PPhTQ thin film phototransistor exhibits an excellent device performance with a maximum photoresponsivity of 400 A/W.
Co-reporter:Shoufa Zhou, Cunbin An, Timea Stelzig, Sreenivasa Reddy Puniredd, Xin Guo, Wojciech Pisula and Martin Baumgarten
New Journal of Chemistry 2015 vol. 39(Issue 9) pp:6765-6770
Publication Date(Web):04 Jun 2015
DOI:10.1039/C5NJ00517E
The synthesis and characterization of fused-ring thiadiazoloquinoxaline derivatives are described. The target molecules were studied by UV-Vis absorption, emission spectroscopy and cyclic voltammetry. The optical absorption maximum λmax of the new molecules in solution were shown at 714–774 nm, with the corresponding optical gaps (Eoptg) of 1.44–1.50 eV. Density functional theory calculations were applied for the design and prediction of HOMO and LUMO variations and the corresponding optical absorptions. The thiadiazoloquinoxaline with a phenanthroline moiety showed a liquid crystalline phase as found from 2D-WAXS studies and an electron transporting behavior indicating its potential as an acceptor building block.
Co-reporter:Jungho Lee;Tomasz Marszalek;Kyu Cheol Lee;Jonggi Kim;Changduk Yang
Macromolecular Chemistry and Physics 2015 Volume 216( Issue 11) pp:1244-1250
Publication Date(Web):
DOI:10.1002/macp.201500087
Co-reporter:Unsal Koldemir, Sreenivasa Reddy Puniredd, Manfred Wagner, Sefaattin Tongay, Tracy D. McCarley, George Dimitrov Kamenov, Klaus Müllen, Wojciech Pisula, and John R. Reynolds
Macromolecules 2015 Volume 48(Issue 18) pp:6369-6377
Publication Date(Web):September 3, 2015
DOI:10.1021/acs.macromol.5b01252
Optimized microstructure through control of both intra- and intermolecular interactions in organic semiconductors is critical for enhancing and optimizing charge transport for the realization of next-generation low-cost, mechanically flexible, and easy to process high performance, organic field effect transistors (OFETs). Herein, we report donor–acceptor alternating copolymers of dithienogermole (DTG) with 2,1,3-benzothiadiazole (BTD) and probe the importance of end groups on the control of molecular order and microstructure as it relates to the enhancement of charge carrier transport. Partial end-capping reactions, confirmed by 1H NMR and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analyses, on the DTG–BTD copolymer provided significant improvement in grazing incidence wide angle X-Ray scattering (GIWAXS) determined polymer ordering in thin films. Consequently, OFETs exhibited charge-carrier mobilities up to 0.60 cm2/(Vs) for the end-capped copolymer, which are an order of magnitude higher in comparison to the non-end-capped analogue, which displayed a mobility of 0.077 cm2/(Vs). We emphasize that a simple synthetic approach, the introduction of end-capping groups which remove reactive functionalities, can be effective in the development of next-generation OFET and solar materials by promising better control of the polymer organization.
Co-reporter:Glauco Battagliarin;Sreenivasa Reddy Puniredd;Sebastian Stappert;Wojciech Zajaczkowski;Suhao Wang;Chen Li;Klaus Müllen
Advanced Functional Materials 2014 Volume 24( Issue 47) pp:7530-7537
Publication Date(Web):
DOI:10.1002/adfm.201401573
In this paper n-type semiconductors synthesized via selective fourfold cyanation of the ortho- and bay-positions (2,5,10,13- and 1,6,9,14-positions respectively) of teyrrylenediimides are reported. A detailed study about the impact of the diverse functionalization topologies on the optoelectronic properties, self-organization from solution, solid-state packing, and charge carrier transport in field-effect transistors is presented. The ortho-substitution preserves the planarity of the core and favors high order in solution processed films. However, the strong intermolecular interactions lead to a microstructure with large aggregates and pronounced grain boundaries which lower the charge carrier transport in transistors. In contrast, the well-soluble bay-functionalized terrylenediimide forms only disordered films which surprisingly result in n-type average mobilities of 0.17 cm2/Vs after drop-casting with similar values in air. Processing by solvent vapor diffusion enhances the transport to 0.65 cm2/Vs by slight improvement of the order and surface arrangement of the molecules. This mobility is comparable to highest n-type conductivities measured for solution processed PDI derivatives demonstrating the high potential of TDI-based semiconductors.
Co-reporter:Felix Hinkel, Tomasz Marszalek, Wojciech Zajaczkowski, Sreenivasa Reddy Puniredd, Martin Baumgarten, Wojciech Pisula, and Klaus Müllen
Chemistry of Materials 2014 Volume 26(Issue 16) pp:4844
Publication Date(Web):August 5, 2014
DOI:10.1021/cm5021355
The impact of alkenyl substituents on the behavior of cyclopentadithiophene–benzothiadiazole (CDT–BTZ) donor (D)–acceptor (A) polymers in organic field-effect transistors (OFETs) and on the supramolecular organization was investigated. Linear cis- and trans-alkenes were attached to the donor unit of CDT–BTZ polymers to demonstrate the dependence of supramolecular ordering and solubility in organic solvents on chemical conformation. The layer interdigitation of the substituents differed due to shape disparities between cis- and trans-alkenes. While trans-alkenes exhibit zigzag structures that are beneficial for close packing, cis-alkenes are curved and thus possess a less regular shape that is disadvantageous to thin film ordering. This was proven by grazing incidence wide-angle X-ray scattering (GIWAXS) studies, which revealed shorter intermolecular distances for the polymer with trans-alkene substituents even in comparison to analogous polymers with saturated alkyl substituents. Furthermore, the isomerization of the cis-substituents toward their trans-conformers allowed improvement of the polymer crystallinity in thin films and was investigated in transistor devices and solubility studies.
Co-reporter:Thorsten Rieth;Dr. Tomasz Marszalek;Dr. Wojciech Pisula;Dr. Heiner Detert
Chemistry - A European Journal 2014 Volume 20( Issue 17) pp:5000-5006
Publication Date(Web):
DOI:10.1002/chem.201400034
Abstract
Tristriazolotriazines with a threefold dialkoxyaryl substitution have been prepared by Huisgen reaction of cyanuric chloride and the corresponding tetrazoles. Although these dyes show a negative or inverted solvatochromism of the UV/Vis absorption, their fluorescence is strongly positive solvatochromic. These discotic fluorophores are also emissive in their solid state and in their broad liquid-crystalline mesophase. The structural study indicates that the thermotropic properties and organization of these systems can be well tuned by the steric demand of the aryl groups. Depending on the substituents, the compounds showed either a pure crystalline phase or a highly complex helical superstructure with a characteristic liquid-crystalline phase at elevated temperatures. Changing the steric demand of the attached aryls allowed controlling the discs arrangement within the columnar helix, which is of great importance for the molecular orbital overlap.
Co-reporter:Xin Guo;Sreenivasa Reddy Puniredd;Martin Baumgarten;Klaus Müllen
Advanced Materials 2013 Volume 25( Issue 38) pp:5467-5472
Publication Date(Web):
DOI:10.1002/adma.201302052
Co-reporter:Jie Shu ; Dmytro Dudenko ; Morteza Esmaeili ; Jun Ha Park ; Sreenivasa Reddy Puniredd ; Ji Young Chang ; Dag Werner Breiby ; Wojciech Pisula ;Michael Ryan Hansen
Journal of the American Chemical Society 2013 Volume 135(Issue 30) pp:11075-11086
Publication Date(Web):July 5, 2013
DOI:10.1021/ja4029186
Discotic hydrazone molecules are of particular interest as they form discotic phases where the discs are rigidified by intramolecular hydrogen bonds. Here, we investigate the thermotropic behavior and solid-state organizations of three discotic hydrazone derivatives with dendritic groups attached to their outer peripheries, containing six, eight, and ten carbons of linear alkoxy chains. On the basis of two-dimensional wide angle X-ray scattering (2DWAXS), the elevated temperature liquid crystalline (LC) phases were assigned to a hexagonal columnar (Colh) organization with nontilted hydrazone discs for all three compounds. With WAXS, advanced solid-state nuclear magnetic resonance (SSNMR) techniques, and ab initio computations, the compounds with six and ten carbons of achiral alkoxy side chains were further subjected to studies at 25 °C, revealing complex crystalline phases with rigid columns and flexible side chains. This combined approach led to models of coexisting helical columnar stacking morphologies for both systems with two different tilt/pitch angles between successive hydrazone molecules. The differences in tilt/pitch angles between the two compounds illustrate that the columns with short alkoxy chains (six carbons) are more influenced by the presence of other stacks in their vicinity, while those with long side chains are less tilted due to a larger alkoxy (ten carbons) buffer zone. The formation of different packing morphologies in the crystalline phase of a columnar LC has rarely been reported so far, which suggests the possibility of complex stacking structures of similar organic LC systems, utilizing small molecules as potential materials for applications in organic electronics.
Co-reporter:Sreenivasa Reddy Puniredd, Adam Kiersnowski, Glauco Battagliarin, Wojciech Zajączkowski, Wallace W. H. Wong, Nigel Kirby, Klaus Müllen and Wojciech Pisula
Journal of Materials Chemistry A 2013 vol. 1(Issue 13) pp:2433-2440
Publication Date(Web):29 Jan 2013
DOI:10.1039/C3TC00562C
Thin film field-effect transistors based on binary blends of poly(3-hexylthiophene) (P3HT) and two perylene diimide (PDI) derivatives with different alkyl substituents have been investigated in terms of device performance, microstructure and molecular organization on the surface. For the same blend ratios the PDIs phase separate differently due to solubility variation. Blends with a horizontal phase separation between the donor and acceptor show ambipolar behavior due to well defined homogenous pathways for both charge carriers. In this layer arrangement the polymer is located near the dielectric interface, while the PDI molecules crystallize on top of the film. Interestingly, the electron mobility is improved by a few orders of magnitude in comparison to the pure acceptor. This increase is attributed to the altered microstructure of PDI in the blends. Layers in which the PDI crystals are embedded within the polymer matrix and are not interconnected with each other lead only to hole transport in the transistor. For one blend ratio, the hole mobility improves by one order of magnitude compared to pure P3HT as a result of the reorganization of the polymer in the blend layer. This study provides new insights into the role of microstructure and molecular organization in the charge carrier transport in heterojunction field-effect transistors for the development of high-performance future devices.
Co-reporter:Suhao Wang;Michael Kappl;Ingo Liebewirth;Maren Müller;Katrin Kirchhoff;Klaus Müllen
Advanced Materials 2012 Volume 24( Issue 3) pp:417-420
Publication Date(Web):
DOI:10.1002/adma.201103057
Co-reporter:Suhao Wang ; Adam Kiersnowski ; Wojciech Pisula ;Klaus Müllen
Journal of the American Chemical Society 2012 Volume 134(Issue 9) pp:4015-4018
Publication Date(Web):February 21, 2012
DOI:10.1021/ja211630w
Probing the role of the first monolayer in the evolution of the film polymer microstructure is essential for the fundamental understanding of the charge carrier transport in polymeric field-effect transistors (FETs). The monolayer and its subsequent microstructure of a conjugated polymer [poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene), PBTTT] film were fabricated via solution deposition by tuning the dip-coating speed and were then studied as accumulation and transporting layers in FETs. Investigation of the microstructure of the layers prepared at different coating velocities revealed that the monolayer serves as an important base for further development of the film. Significant improvement of the charge carrier transport occurs only at a critical multilayer network density that establishes the required percolation pathways for the charge carriers. Finally, at a low dip-coating speed, the polymer chains are uniaxially oriented, yielding pronounced structural anisotropy and high charge carrier mobilities of 1.3 cm2 V–1 s–1 in the alignment direction.
Co-reporter:Suhao Wang, Wojciech Pisula and Klaus Müllen
Journal of Materials Chemistry A 2012 vol. 22(Issue 47) pp:24827-24831
Publication Date(Web):01 Oct 2012
DOI:10.1039/C2JM35351B
The nanofiber growth of an n-type conjugated polymer poly{[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)}, P(NDI2OD-T2), was studied during solution processing. Highly reproducible fibrous nanostructures obtained at various dip coating speeds provide an insight into the growth mechanism of the polymer nanofibers during solution deposition and into the correlation between their morphology and charge-carrier mobility of organic field-effect transistors (OFETs). Remarkably, the nanofibers orient parallel to the dip coating direction on reaching 4 layers leading to a significantly improved charge transport between source and drain electrodes. We have observed that the morphology, thickness and orientation have great impacts on the charge carrier transport. We prove that the first fully covered fibrous layer is of minimum thickness for a charge carrier migration to happen in the transistor, whereas the mobility strongly rises in the subsequent 3–4 fibrous layers, which are considered to provide alternative pathways for charge carriers. The strong increase in the thickness of 3–4 layers is also attributed to the additional film alignment taking place during the dip coating process. Therefore, the type of fibrous nanostructures does not change with film thickness.
Co-reporter:Hoi Nok Tsao ; Don M. Cho ; Insun Park ; Michael Ryan Hansen ; Alexey Mavrinskiy ; Do Y. Yoon ; Robert Graf ; Wojciech Pisula ; Hans Wolfgang Spiess ;Klaus Müllen
Journal of the American Chemical Society 2011 Volume 133(Issue 8) pp:2605-2612
Publication Date(Web):February 3, 2011
DOI:10.1021/ja108861q
In this article, the design paradigm involving molecular weight, alkyl substituents, and donor−acceptor interaction for the poly[2,6-(4,4-bis-alkyl-4H-cyclopenta[2,1-b;3,4-b′]-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (cyclopentadithiophene−benzothiadiazole) donor−acceptor copolymer (CDT−BTZ) toward field-effect transistors (FETs) with ultrahigh mobilities is presented and discussed. It is shown that the molecular weight plays a key role in improving hole mobilities, reaching an exceptionally high value of up to 3.3 cm2 V−1 s−1. Possible explanations for this observation is highlighted in conjunction with thin film morphology and crystallinity. Hereby, it is found that the former does not change, whereas, at the same time, crystallinity improved with ever growing molecular weight. Furthermore, other important structural design factors such as alkyl chain substituents and donor−acceptor interaction between the polymer backbones potentially govern intermolecular stacking distances crucial for charge transport and hence for device performance. In this aspect, for the first time we attempt to shed light onto donor−acceptor interactions between neighboring polymer chains with the help of solid state nuclear magnetic resonance (NMR). On the basis of our results, polymer design principles are inferred that might be of relevance for prospective semiconductors exhibiting hole mobilities even exceeding 3 cm2 V−1 s−1.
Co-reporter:Alexey Mavrinskiy, Christian B. Nielsen, John R. Reynolds, Klaus Müllen, and Wojciech Pisula
Chemistry of Materials 2011 Volume 23(Issue 7) pp:1939
Publication Date(Web):March 1, 2011
DOI:10.1021/cm1036716
The organization of a series of phenylene−thienylene-based oligomers solubilized with terminal (ω-hydroxyalkyl) and lateral (alkoxy) side chains was studied. The thermal behavior and self-assembly on the surface during solution and thermal processing are mainly affected by the position and length of the side chains. The molecules organize in different fashions, depending on the substitution pattern, as indicated by fiber X-ray scattering results. The oligomer with only lateral side chains behaves as a typical rigid rod arranged in lamella structures, while those with a homogeneous alkyl mantle around the aromatic system adapt a disklike character and form one-dimensional stacks. Because of the large aromatic rod, the role of the terminal hydroxy groups on the self-assembly can be neglected. The choice of the alkyl density around the aromatic core allows a control over the molecular organization, which is essential for the development of high-performance solution-processable organic semiconductors.Keywords: phenylene thienylene oligomer; self-assembly; supramolecular organization; wide-angle X-ray scattering;
Co-reporter:Suhao Wang, Peng Gao, Ingo Liebewirth, Katrin Kirchhoff, Shuping Pang, Xinliang Feng, Wojciech Pisula, and Klaus Müllen
Chemistry of Materials 2011 Volume 23(Issue 22) pp:4960
Publication Date(Web):October 19, 2011
DOI:10.1021/cm202844g
Well-defined DTBDT crystal microribbons were fabricated by a solution processing method named as solvent vapor diffusion directly on the surface. This procedure is based on exposing a drop cast solution to a saturated solvent vapor atmosphere and allows to tune the dimensions of the ribbons simply by controlling the concentration of the solution. The structural study indicates single crystallinity and a molecular organization in the ribbons that is considered to be favorable for the carrier transport along ribbon axis. In the device, individual crystal DTBDT organic field-effect transistors exhibit mobilities as high as 3.2 cm2 V–1 s–1 and on/off ratios up to 1 × 106. This processing approach can be further exploited for a broad range of other (macro)molecular semiconductors and additionally bears great potential for practical applications.Keywords: field-effect transistor; microribbon; organic electronics; self-assembly; solution processing;
Co-reporter:Yan Li, Linxiao Hao, Hongbing Fu, Wojciech Pisula, Xinliang Feng and Zhaohui Wang
Chemical Communications 2011 vol. 47(Issue 36) pp:10088-10090
Publication Date(Web):10 Aug 2011
DOI:10.1039/C1CC13398E
Columnar liquid crystalline bis-N-annulated quaterrylenes have been prepared from readily available N-annulated perylenes by DDQ/Sc(OTf)3 oxidative coupling and ring-fusion.
Co-reporter:Suhao Wang;Dr. Milan Kivala;Dr. Ingo Lieberwirth;Katrin Kirchhoff;Dr. Xinliang Feng;Dr. Wojciech Pisula; Dr. Klaus Müllen
ChemPhysChem 2011 Volume 12( Issue 9) pp:1648-1651
Publication Date(Web):
DOI:10.1002/cphc.201100199
Co-reporter:Wojciech Pisula;Xinliang Feng;Klaus Müllen
Advanced Materials 2010 Volume 22( Issue 33) pp:3634-3649
Publication Date(Web):
DOI:10.1002/adma.201000585
Co-reporter:Wojciech Pisula;Xinliang Feng;Klaus Müllen
Advanced Materials 2010 Volume 22( Issue 33) pp:
Publication Date(Web):
DOI:10.1002/adma.201090109
Co-reporter:Hoi Nok Tsao;Don Cho;Jens Wenzel Andreasen;Ali Rouhanipour;Dag W. Breiby;Klaus Müllen
Advanced Materials 2009 Volume 21( Issue 2) pp:209-212
Publication Date(Web):
DOI:10.1002/adma.200802032
Co-reporter:Hoi Nok Tsao;Don Cho;Jens Wenzel Andreasen;Ali Rouhanipour;Dag W. Breiby;Klaus Müllen
Advanced Materials 2009 Volume 21( Issue 2) pp:
Publication Date(Web):
DOI:10.1002/adma.200990000
Co-reporter:Hoi Nok Tsao;Zhihong Liu;Wojciech Osikowicz;William R. Salaneck;Klaus Müllen
Advanced Materials 2008 Volume 20( Issue 14) pp:2715-2719
Publication Date(Web):
DOI:10.1002/adma.200702992
Co-reporter:Xinliang Feng;Miaoyin Liu;Masayoshi Takase;Jiaoli Li;Klaus Müllen
Advanced Materials 2008 Volume 20( Issue 14) pp:2684-2689
Publication Date(Web):
DOI:10.1002/adma.200800642
Co-reporter:Xinliang Feng;Miaoyin Liu;Masayoshi Takase;Jiaoli Li;Klaus Müllen
Advanced Materials 2008 Volume 20( Issue 14) pp:
Publication Date(Web):
DOI:10.1002/adma.200890054
Co-reporter:Wojciech Pisula, Željko Tomović, Martin Wegner, Robert Graf, Maarten J. Pouderoijen, E. W. Meijer and Albertus P. H. J. Schenning
Journal of Materials Chemistry A 2008 vol. 18(Issue 25) pp:2968-2977
Publication Date(Web):28 May 2008
DOI:10.1039/B803117G
The thermotropic behaviour of a series of hydrogen bonded chiral and achiral oligo(p-phenylenevinylenes) (OPVs) has been investigated. The liquid crystalline properties are studied as a function of their molecular design that is based on hydrogen bonding units, the lengths of the π-conjugated and flexible segments and the branching of the side chains. Two-dimensional wide-angle X-ray scattering experiments indicate self-assembly of all OPVs into columnar superstructures which is the result of hydrogen bonds formed by the diaminotriazine or ureidotriazine units and π-stacking interactions accompanied by a local phase separation between the alkoxy side chains and the aromatic rods. The phase behaviour of the compounds bearing the diaminotriazine functionality depends on the length of the OPV segment. OPV trimers are already liquid crystalline at ambient conditions, while longer OPV tetramers are in a well-organized crystalline state at that temperature. In the liquid crystalline phase the intracolumnar order decreases due to molecular motion as confirmed by solid-state NMR studies. Interestingly, the introduction of branched (S)-2-methylbutoxy side chains increases significantly the π-stacking distance while the dimensions of the hexagonal unit cell decrease. The hydrogen bonding ureidotriazine groups decrease the thermal stability and lower the degree of order in comparison with the diaminotriazine derivatives. This low degree of order is probably the result of the ureidotriazine units that form hydrogen bonded dimers while the diaminotriazine arrays form hydrogen bonded hexameric rosettes. In the latter case a more densely packed columnar structure is formed.
Co-reporter:Tomasz Marszalek, Mengmeng Li and Wojciech Pisula
Chemical Communications 2016 - vol. 52(Issue 73) pp:NaN10947-10947
Publication Date(Web):2016/07/07
DOI:10.1039/C6CC04523E
Donor–acceptor polymers with an alternating array of donor and acceptor moieties have gained particular attention during recent years as active components of organic electronics. By implementation of suitable subunits within the conjugated backbone, these polymers can be made either electron-deficient or -rich. Additionally, their band gap and light absorption can be precisely tuned for improved light-harvesting in solar cells. On the other hand, the polymer design can also be modified to encode the desired supramolecular self-assembly in the solid-state that is essential for an unhindered transport of charge carriers. This review focuses on three major factors playing a role in the assembly of donor–acceptor polymers on surfaces which are (1) nature, geometry and substitution position of solubilizing alkyl side chains, (2) shape of the conjugated polymer defined by the backbone curvature, and (3) molecular weight which determines the conjugation length of the polymer. These factors adjust the fine balance between attractive and repulsive forces and ensure a close polymer packing important for an efficient charge hopping between neighboring chains. On the microscopic scale, an appropriate domain formation with a low density of structural defects in the solution deposited thin film is crucial for the charge transport. The charge carrier transport through such thin films is characterized by field-effect transistors as basic electronic elements.
Co-reporter:Yan Li, Linxiao Hao, Hongbing Fu, Wojciech Pisula, Xinliang Feng and Zhaohui Wang
Chemical Communications 2011 - vol. 47(Issue 36) pp:NaN10090-10090
Publication Date(Web):2011/08/10
DOI:10.1039/C1CC13398E
Columnar liquid crystalline bis-N-annulated quaterrylenes have been prepared from readily available N-annulated perylenes by DDQ/Sc(OTf)3 oxidative coupling and ring-fusion.
Co-reporter:Suhao Wang, Wojciech Pisula and Klaus Müllen
Journal of Materials Chemistry A 2012 - vol. 22(Issue 47) pp:NaN24831-24831
Publication Date(Web):2012/10/01
DOI:10.1039/C2JM35351B
The nanofiber growth of an n-type conjugated polymer poly{[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)}, P(NDI2OD-T2), was studied during solution processing. Highly reproducible fibrous nanostructures obtained at various dip coating speeds provide an insight into the growth mechanism of the polymer nanofibers during solution deposition and into the correlation between their morphology and charge-carrier mobility of organic field-effect transistors (OFETs). Remarkably, the nanofibers orient parallel to the dip coating direction on reaching 4 layers leading to a significantly improved charge transport between source and drain electrodes. We have observed that the morphology, thickness and orientation have great impacts on the charge carrier transport. We prove that the first fully covered fibrous layer is of minimum thickness for a charge carrier migration to happen in the transistor, whereas the mobility strongly rises in the subsequent 3–4 fibrous layers, which are considered to provide alternative pathways for charge carriers. The strong increase in the thickness of 3–4 layers is also attributed to the additional film alignment taking place during the dip coating process. Therefore, the type of fibrous nanostructures does not change with film thickness.
Co-reporter:Wojciech Pisula, Željko Tomović, Martin Wegner, Robert Graf, Maarten J. Pouderoijen, E. W. Meijer and Albertus P. H. J. Schenning
Journal of Materials Chemistry A 2008 - vol. 18(Issue 25) pp:NaN2977-2977
Publication Date(Web):2008/05/28
DOI:10.1039/B803117G
The thermotropic behaviour of a series of hydrogen bonded chiral and achiral oligo(p-phenylenevinylenes) (OPVs) has been investigated. The liquid crystalline properties are studied as a function of their molecular design that is based on hydrogen bonding units, the lengths of the π-conjugated and flexible segments and the branching of the side chains. Two-dimensional wide-angle X-ray scattering experiments indicate self-assembly of all OPVs into columnar superstructures which is the result of hydrogen bonds formed by the diaminotriazine or ureidotriazine units and π-stacking interactions accompanied by a local phase separation between the alkoxy side chains and the aromatic rods. The phase behaviour of the compounds bearing the diaminotriazine functionality depends on the length of the OPV segment. OPV trimers are already liquid crystalline at ambient conditions, while longer OPV tetramers are in a well-organized crystalline state at that temperature. In the liquid crystalline phase the intracolumnar order decreases due to molecular motion as confirmed by solid-state NMR studies. Interestingly, the introduction of branched (S)-2-methylbutoxy side chains increases significantly the π-stacking distance while the dimensions of the hexagonal unit cell decrease. The hydrogen bonding ureidotriazine groups decrease the thermal stability and lower the degree of order in comparison with the diaminotriazine derivatives. This low degree of order is probably the result of the ureidotriazine units that form hydrogen bonded dimers while the diaminotriazine arrays form hydrogen bonded hexameric rosettes. In the latter case a more densely packed columnar structure is formed.
Co-reporter:Sreenivasa Reddy Puniredd, Adam Kiersnowski, Glauco Battagliarin, Wojciech Zajączkowski, Wallace W. H. Wong, Nigel Kirby, Klaus Müllen and Wojciech Pisula
Journal of Materials Chemistry A 2013 - vol. 1(Issue 13) pp:NaN2440-2440
Publication Date(Web):2013/01/29
DOI:10.1039/C3TC00562C
Thin film field-effect transistors based on binary blends of poly(3-hexylthiophene) (P3HT) and two perylene diimide (PDI) derivatives with different alkyl substituents have been investigated in terms of device performance, microstructure and molecular organization on the surface. For the same blend ratios the PDIs phase separate differently due to solubility variation. Blends with a horizontal phase separation between the donor and acceptor show ambipolar behavior due to well defined homogenous pathways for both charge carriers. In this layer arrangement the polymer is located near the dielectric interface, while the PDI molecules crystallize on top of the film. Interestingly, the electron mobility is improved by a few orders of magnitude in comparison to the pure acceptor. This increase is attributed to the altered microstructure of PDI in the blends. Layers in which the PDI crystals are embedded within the polymer matrix and are not interconnected with each other lead only to hole transport in the transistor. For one blend ratio, the hole mobility improves by one order of magnitude compared to pure P3HT as a result of the reorganization of the polymer in the blend layer. This study provides new insights into the role of microstructure and molecular organization in the charge carrier transport in heterojunction field-effect transistors for the development of high-performance future devices.
![4H,8H,12H-Benzo[1,9]quinolizino[3,4,5,6,7-defg]acridine-4,8,12-trione, 2,6,10-triiodo-](/data/chemimg/139700/1169703-57-4.png)
![4H,8H,12H-Benzo[1,9]quinolizino[3,4,5,6,7-defg]acridine-4,8,12-trione, 2,6,10-triiodo-](/data/chemimg/139700/1169703-57-4_b.png)
![2,10,18-Tris(2-decyltetradecyl)-benzo[o]bistriphenyleno[2,1,12,11-efghi:2',1',12',11'-uvabc]ovalene](http://img.cochemist.com/ccimg/1061200/1061170-68-0.png)
![2,10,18-Tris(2-decyltetradecyl)-benzo[o]bistriphenyleno[2,1,12,11-efghi:2',1',12',11'-uvabc]ovalene](http://img.cochemist.com/ccimg/1061200/1061170-68-0_b.png)
![4H-Cyclopenta[2,1-b:3,4-b']dithiophene, 2,6-dibromo-4,4-bis(2-ethylhexyl)-](/data/chemimg/542100/365547-21-3.png)
![4H-Cyclopenta[2,1-b:3,4-b']dithiophene, 2,6-dibromo-4,4-bis(2-ethylhexyl)-](/data/chemimg/542100/365547-21-3_b.png)
![Stannane, trimethyl(5-octylthieno[3,2-b]thien-2-yl)-](/data/chemimg/139500/1403780-82-4.png)
![Stannane, trimethyl(5-octylthieno[3,2-b]thien-2-yl)-](/data/chemimg/139500/1403780-82-4_b.png)
![4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[c][1,2,5]thiadiazole](http://img.cochemist.com/ccimg/1088200/1088118-97-1.png)
![4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[c][1,2,5]thiadiazole](http://img.cochemist.com/ccimg/1088200/1088118-97-1_b.png)
![Stannane, 1,1'-(3,3'-didodecyl[2,2'-bithiophene]-5,5'-diyl)bis[1,1,1-trimethyl-](/data/chemimg/158700/1048694-54-7.png)
![Stannane, 1,1'-(3,3'-didodecyl[2,2'-bithiophene]-5,5'-diyl)bis[1,1,1-trimethyl-](/data/chemimg/158700/1048694-54-7_b.png)
![Thieno[3,2-b]thiophene, 2-octyl-](/data/chemimg/139400/1042737-17-6.png)
![Thieno[3,2-b]thiophene, 2-octyl-](/data/chemimg/139400/1042737-17-6_b.png)
![1,2-ETHANEDIONE, 1,2-BIS[4-[(2-DECYLTETRADECYL)OXY]PHENYL]-](http://img.cochemist.com/ccimg/916900/916841-13-9.png)
![1,2-ETHANEDIONE, 1,2-BIS[4-[(2-DECYLTETRADECYL)OXY]PHENYL]-](http://img.cochemist.com/ccimg/916900/916841-13-9_b.png)
![Poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene]](http://img.cochemist.com/ccimg/888500/888491-19-8.png)
![Poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene]](http://img.cochemist.com/ccimg/888500/888491-19-8_b.png)
![14H-Dibenzo[a,j]thioxanthene, 14-phenyl-](http://img.cochemist.com/ccimg/854400/854393-36-5.png)
![14H-Dibenzo[a,j]thioxanthene, 14-phenyl-](http://img.cochemist.com/ccimg/854400/854393-36-5_b.png)
![[1,1':4',1''-TERPHENYL]-2',5'-DICARBOXALDEHYDE, 2,2''-DICHLORO-](http://img.cochemist.com/ccimg/705300/705289-87-8.png)
![[1,1':4',1''-TERPHENYL]-2',5'-DICARBOXALDEHYDE, 2,2''-DICHLORO-](http://img.cochemist.com/ccimg/705300/705289-87-8_b.png)
![2,5-Bis(trimethylstannyl)thieno[3,2-b]thiophene](http://img.cochemist.com/ccimg/470000/469912-82-1.png)
![2,5-Bis(trimethylstannyl)thieno[3,2-b]thiophene](http://img.cochemist.com/ccimg/470000/469912-82-1_b.png)
![2H-Cyclopenta[l]phenanthren-2-one, 6,9-dibromo-1,3-diphenyl-](http://img.cochemist.com/ccimg/384900/384824-44-6.png)
![2H-Cyclopenta[l]phenanthren-2-one, 6,9-dibromo-1,3-diphenyl-](http://img.cochemist.com/ccimg/384900/384824-44-6_b.png)
![Dibenzo[a,j]xanthenium,14-phenyl-, bromide (1:1)](http://img.cochemist.com/ccimg/294700/294627-85-3.png)
![Dibenzo[a,j]xanthenium,14-phenyl-, bromide (1:1)](http://img.cochemist.com/ccimg/294700/294627-85-3_b.png)
![[1,1'-Biphenyl]-4-acetic acid, 4'-iodo-, ethyl ester](http://img.cochemist.com/ccimg/166900/166891-84-5.png)
![[1,1'-Biphenyl]-4-acetic acid, 4'-iodo-, ethyl ester](http://img.cochemist.com/ccimg/166900/166891-84-5_b.png)
![4H-Cyclopenta[2,1-b:3,4-b']dithiophene, 4,4-dihexadecyl-](/data/chemimg/110300/153312-88-0.png)
![4H-Cyclopenta[2,1-b:3,4-b']dithiophene, 4,4-dihexadecyl-](/data/chemimg/110300/153312-88-0_b.png)
![4,4'-Dibromo-[1,1'-biphenyl]-2,2'-diamine](http://img.cochemist.com/ccimg/136700/136630-36-9.png)
![4,4'-Dibromo-[1,1'-biphenyl]-2,2'-diamine](http://img.cochemist.com/ccimg/136700/136630-36-9_b.png)
![Thiophene, 2,2'-[2,5-bis(hexadecyloxy)-1,4-phenylene]bis-](http://img.cochemist.com/ccimg/135900/135859-76-6.png)
![Thiophene, 2,2'-[2,5-bis(hexadecyloxy)-1,4-phenylene]bis-](http://img.cochemist.com/ccimg/135900/135859-76-6_b.png)
![Benzo[o]bistriphenyleno[2,1,12,11-efghi:2',1',12',11'-uvabc]ovalene](http://img.cochemist.com/ccimg/123200/123178-24-5.png)
![Benzo[o]bistriphenyleno[2,1,12,11-efghi:2',1',12',11'-uvabc]ovalene](http://img.cochemist.com/ccimg/123200/123178-24-5_b.png)
![Diphenanthro[3,4,5,6-efghi:3',4',5',6'-uvabc]ovalene](http://img.cochemist.com/ccimg/94500/94417-44-4.png)
![Diphenanthro[3,4,5,6-efghi:3',4',5',6'-uvabc]ovalene](http://img.cochemist.com/ccimg/94500/94417-44-4_b.png)
![14H-Dibenzo[a,j]xanthene, 14-phenyl-](http://img.cochemist.com/ccimg/36500/36441-29-9.png)
![14H-Dibenzo[a,j]xanthene, 14-phenyl-](http://img.cochemist.com/ccimg/36500/36441-29-9_b.png)
![Poly[oxy(2,6-dimethyl-1,4-phenylene)]](http://img.cochemist.com/ccimg/25000/24938-67-8.png)
![Poly[oxy(2,6-dimethyl-1,4-phenylene)]](http://img.cochemist.com/ccimg/25000/24938-67-8_b.png)
![Silane, [4-(bromomethyl)phenyl]trimethyl-](http://img.cochemist.com/ccimg/18000/17903-42-3.png)
![Silane, [4-(bromomethyl)phenyl]trimethyl-](http://img.cochemist.com/ccimg/18000/17903-42-3_b.png)
![dibenzo[ghi,mno]fluoranthene](http://img.cochemist.com/ccimg/5900/5821-51-2.png)
![dibenzo[ghi,mno]fluoranthene](http://img.cochemist.com/ccimg/5900/5821-51-2_b.png)
![Benzo[1,2-b:4,5-b']bis[1]benzothiophene](http://img.cochemist.com/ccimg/300/241-34-9.png)
![Benzo[1,2-b:4,5-b']bis[1]benzothiophene](http://img.cochemist.com/ccimg/300/241-34-9_b.png)
![BENZO[13,14]PENTAPHENO[3,4,5-DEF:10,9,8-D'E'F']DIISOQUINOLINE-1,3,10,12(2H,11H)-TETRONE, 2,11-BIS(1-HEPTYLOCTYL)-](http://img.cochemist.com/ccimg/881900/881877-80-1.png)
![BENZO[13,14]PENTAPHENO[3,4,5-DEF:10,9,8-D'E'F']DIISOQUINOLINE-1,3,10,12(2H,11H)-TETRONE, 2,11-BIS(1-HEPTYLOCTYL)-](http://img.cochemist.com/ccimg/881900/881877-80-1_b.png)
![1-(2-DECYLTETRADECYL)-4-[2-[4-(2-DECYLTETRADECYL)PHENYL]ETHYNYL]BENZENE](http://img.cochemist.com/ccimg/732300/732276-65-2.png)
![1-(2-DECYLTETRADECYL)-4-[2-[4-(2-DECYLTETRADECYL)PHENYL]ETHYNYL]BENZENE](http://img.cochemist.com/ccimg/732300/732276-65-2_b.png)
![Silane, [(4'-bromo[1,1'-biphenyl]-4-yl)ethynyl]trimethyl-](http://img.cochemist.com/ccimg/377800/377754-07-9.png)
![Silane, [(4'-bromo[1,1'-biphenyl]-4-yl)ethynyl]trimethyl-](http://img.cochemist.com/ccimg/377800/377754-07-9_b.png)
![Benzo[2,1-b:3,4-b']dithiophene-4,5-dione](/data/chemimg/1467500/24243-32-1.png)
![Benzo[2,1-b:3,4-b']dithiophene-4,5-dione](/data/chemimg/1467500/24243-32-1_b.png)
![Ethanol, 2-[2-(2-methoxyethoxy)ethoxy]-, 1-(4-methylbenzenesulfonate)](/data/chemimg/636900/62921-74-8.png)
![Ethanol, 2-[2-(2-methoxyethoxy)ethoxy]-, 1-(4-methylbenzenesulfonate)](/data/chemimg/636900/62921-74-8_b.png)
![Hexabenzo[bc,ef,hi,kl,no,qr]coronene](/data/chemimg/1472400/190-24-9.png)
![Hexabenzo[bc,ef,hi,kl,no,qr]coronene](/data/chemimg/1472400/190-24-9_b.png)