# Fileset

[main.pdf](https://mdr.nims.go.jp/filesets/571028d9-7f80-49dd-a3d9-dba4ddc0a83c/download)

## Creator

[Shuta Fujioka](https://orcid.org/0009-0001-9595-3714), [Masaki Ishii](https://orcid.org/0009-0008-6846-9610), Jun Takeya, [Katsuhiko Ariga](https://orcid.org/0000-0002-2445-2955), [Yu Yamashita](https://orcid.org/0000-0001-7966-3197)

## Rights

This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in ACS Applied Materials & Interfaces, copyright © 2025 American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/acsami.4c20510. [In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Circular Flow Alignment of Polymeric Semiconductor Thin Films on Air–Liquid Interfaces](https://mdr.nims.go.jp/datasets/68fb3524-42b0-4721-8a28-b3fa072ba5be)

## Fulltext

Circular Flow Alignment of PolymericSemiconductor Thin Films on Air-LiquidInterfacesShuta Fujioka,†,¶ Masaki Ishii,†,‡ Jun Takeya,†,¶ Katsuhiko Ariga,∗,†,‡,¶ and YuYamashita∗,†,¶†Research Center for Materials Nanoarchitectonics (MANA), National Institute forMaterials Science (NIMS), Tsukuba, Japan‡Graduate School of Science and Technology, Tokyo University of Science, Noda, Japan¶Department of Advanced Materials Science, Graduate School of Frontier Sciences,University of Tokyo, Kashiwa, JapanE-mail: ARIGA.Katsuhiko@nims.go.jp; YAMASHITA.Yu@nims.go.jpAbstractOrientational control of polymeric semiconductors (PSs) is a fundamental technol-ogy for understanding and improving the carrier transport properties. Although PSthin films have been fabricated through facile solution processes, complex convectionflows during solvent evaporation often limit the controllability of orientation in terms ofscalability and reproducibility. To address these problems, we developed a circular flowalignment method for PS thin films. On the circularly flowing glycerol inside a con-tainer, PS solutions were dropped to obtain thin films at the air-liquid interface. Theresulting thin films showed alignment of the main chains along the flow direction, wherethe effects of convection flows during solvent evaporation were suppressed. Anisotropic1characteristics were observed in the thin-film structure evaluated by X-ray diffractionmeasurements, optical absorption, and carrier transport properties, which support theuniaxial alignment of the PS main chains. In field-effect transistors, a mobility of 0.13cm2 V−1 s−1 was observed under atmospheric conditions, which was four times higherthan that of spin-coated thin films. Considering that macroscopic liquid flows are easilycontrolled, the proposed flow alignment may serve as a scalable and facile method forfabricating highly aligned PS thin films for various applications.IntroductionPolymeric semiconductors (PSs) feature flexibility, solution processability, and tunable elec-tronic properties by molecular design, which has led to their applications including field-effecttransistors (FETs),1,2 diodes,3,4 and thermoelectric generators.5,6 Alignment of PSs is a keytechnology for understanding and improving their electronic properties.2,7,8 In addition touniaxial alignment of the polymer main chains, it is important to achieve edge-on or face-onorientations depending on the target application. In FETs and applications using lateralcarrier transport, the edge-on orientation is advantageous. Although methods such as high-temperature rubbing,7 solution shearing,9 and bar coating10,11 have yielded highly alignedpolymer chains, the control of edge-on and face-on orientations is not always compatible. Inaddition, when a solution process is employed to fabricate aligned polymer films, multipleconditions need to be optimized under effects such as interactions between the substrate andpolymer solution and convection flows in heated and drying solutions,12 which may limitreproducibility and scalability.Recently, aligned PS thin films with edge-on orientation have been fabricated using air-liquid interfaces.13–18 The fabricated thin films were transferred to the target substrates foruse in devices. The air-liquid interface without attachment to solid substrates seems toallow the self-assembly of PSs into ordered structures by casting polymer solutions on liquidsurfaces. By choosing the appropriate liquid subphase, the Langmuir-Blodgett method on2a heated liquid surface was demonstrated to utilize the compression force as the drivingforce for uniaxial alignment of PSs, which resulted in high mobility and conductivity afterdoping.13,19,20 Despite these advantages, it has been still difficult to control the alignmentdirection in a large area uniformly owing to the complex fluid flow dynamics that are affectedby factors such as solution evaporation and the interaction between the polymer solutionand the liquid substrate. Therefore, the precise control of convection effects during solventevaporation is crucial in solution processes conducted on both liquid and solid substrates.As a versatile alignment method, flow-induced alignment has been commonly employedfor the highly ordered orientation of carbon nanotubes,21 PEDOT:PSS,22 liquid crystal poly-mers23,24 and hydrogels.25 For instance, in the 3D printing of liquid crystal polymers, shearand extensional forces effectively induce uniaxial alignment along the flow direction, result-ing in unprecedented stiffness and toughness of the material.23,24 However, such uniaxialflow alignment methods have been limited to the fabrication of fibrous structures and notthin films with two-dimensional sheet structures, which is critically important for the carriertransport properties.Herein, we developed a novel method to utilize microscopically controlled liquid flow foruniaxial alignment of PSs at the air-liquid interface (Fig. 1a). The PS solutions were cast ona viscous liquid, glycerol, which flowed continuously in a container. Thanks to this controlledliquid flow, PSs main chains were aligned along the flow direction, which was confirmed byX-ray diffraction and polarized optical spectroscopy. Improved carrier transport propertiesalong the alignment direction were evaluated using FETs. Our study highlights a simplemethod to suppress the effects of convection flow during the solution process, which hasoften limited the controllability of various solution processes. Scaling up our method may befeasible by flow path design, which highlights the advantage of using flowing liquid substratesin solution processes.3ab//⊥PDCBTcWavelength (nm)Absorbance//400 500 6001 cmflow⊥100 µm PDCBT PBTTT400 500 600 400 500 6000.000.020.040.060.08PQT0.000.020.040.060.080.000.020.040.060.08//⊥//⊥Figure 1: Circular flow alignment of PS thin films. (a) Illustrations of circular flow alignmentmethod together with the chemical and thin-film structures of PDCBT and a photo offabricated thin film. (b) Microscope images of fabricated ultrathin PDCBT film taken withthe incident polarized light parallel (∥) or perpendicular (⊥). (c) Polarized UV-vis spectraof PDCBT, PQT, and PBTTT thin films fabricated using our method. The incident lightpolarization was parallel or perpendicular to the flow direction.Results and discussionFilm Preparations by the Circular Flow Alignment MethodAs a candidate material showing high carrier mobility and air stability, the polymer semicon-ductor poly[(4,4’-bis(2-butyloctoxycarbonyl-[2,2’-bithiophene]-5,5-diyl)-alt-(2,2’-bithiophene-5,5’-diyl)] (PDCBT) was employed in this study. Compared with the well-studied poly(2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene) (PBTTT),16,26 PDCBT exhibits a shorterπ-stacking distance and a deeper highest occupied molecular orbital (HOMO) energy level.27,284The deep HOMO energy is attributed to the electron-withdrawing carboxylate substitutesin PDCBT, which are advantageous for improving the air stability of FETs29,30 and theperformance of solar cells.27–29The circular flow alignment method was employed to fabricate the oriented PDCBTultrathin films. Fig. 1a shows a schematic illustration of the method in which the polymermain chains are highly aligned along the viscous liquid flow at room temperature. First, aglass cylinder was submerged in a circular container filled with glycerol and then rotated ata speed of 20 rpm. The cylinder was fixed onto a Tornado N(Next) PSTC-103 to preciselycontrol rotational speed. At the cylinder periphery, the rotation speed corresponds to ca. 40mm/s, which is likely sufficient to drive polymer chain alignment, considering that a shearrate of less than 1 mm/s was previously reported to uniaxially align polymer chains duringsolution shearing.9 The inside of the container was covered with a PTFE coating to minimizethe friction between glycerol and the container surface. A single droplet (ca. 30 µL) of thePDCBT solution in a mixture of chloroform and 1-chloronaphthalene was dropped onto theglycerol surface flowing along the bottle rotation. To prevent film formation before spreadingthe solution on the glycerol surface, 1-chloronaphthalene with high boiling point was addedto decrease the evaporation rate of the solvent. The cylinder was rotated until the solventevaporated within 5 min. The resulting film was formed around the cylinder showing a ringshape. Nonuniform films were also observed between the ring-shaped film and the wall of thecontainer, which were not employed in the following experiments. When the target substrateplane was in horizontal contact with the fabricated films, similar to the Langmuir-Schaefermethod,31 the films were easily transferred to the target substrates.Fig. 1b shows the polarized optical microscopy (POM) images of the fabricated PD-CBT film. The incident polarized light was shed from the bottom of the substrate and thetransmitted light was observed using a microscope. The color of the PDCBT film becamedarker when the light polarization was parallel to the flow direction during the film forma-tion process than when they were perpendicular to each other. This result indicates the5macroscopic anisotropy of the fabricated PDCBT films. Optical anisotropy was also con-firmed by polarized UV-vis absorption spectroscopy. To demonstrate the applicability of ourmethod to various PSs, we employed three types of PSs, namely PDCBT, PBTTT andpoly(3,3” ’-didodecyl[2,2’:5’,2”:5”,2” ’-quaterthiophene]-5,5” ’-diyl) (PQT). As shown in Fig.1c, the higher absorbance was observed when the flow direction and light polarization wereparallel to each other, which confirms alignment of main chains to this direction for theemployed PSs. The dichroic ratios were calculated to be 3.5, 5.1, 3.7 for PDCBT, PQT,and PBTTT, respectively, based on the area of absorption peaks with the incident polarizedlight parallel and perpendicular to the flow direction. In the UV-vis spectra of the PDCBTthin film, two peaks were observed at approximately 560 nm and 600 nm, which indicateπ-π interactions in the thin films.29 Details of the thin-film structures are discussed based onX-ray diffraction in the following section. The observed successful alignments of PSs shouldbe ascribed to the continuous flow of glycerol in our system. Here, the system with circularflow provides a facile way to make the PSs in contact with the flowing subphase during theslow solvent evaporation process.6Structural Analysis0.5 1.0 1.5 2.0Intensity1.0 1.2 1.4 1.6 1.8 2.0Intensity//⊥abc dein-plane2.01.51.00.50.0-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0//2.01.51.00.50.0-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0⊥out-of-planeπ stackingflow(010) (100)(200)(100)(200)(010)(100)(200)qxy (Å-1) qz (Å-1)qxy (Å-1)qxy (Å-1)q z (Å-1)q z (Å-1)qxy (Å-1)Figure 2: GIWAXS images of the aligned PDCBT film. GIWAXS images with the incidentX-ray (a) parallel and (b) perpendicular to the flow direction. One-dimensional profiledconverted from the images in the (c) in-plane direction. (d) An out-of-plane diffractionusing the theta/two theta method. (e) Schematics of the uniaxially aligned PDCBT withedge-on orientation.Grazing incident wide-angle X-ray scattering (GIWAXS) was used to investigate the semi-crystalline structures of the PDCBT ultrathin films. The PDCBT ultrathin films weretransferred to the substrate three times to increase the film thickness and scattering intensity(Fig. 2a, b). The scattering image obtained with a single ultrathin film is shown in Fig.S1. Based on the one-dimensional profiles (Fig. 2c, d), the fabricated thin films showed(h00) diffraction peaks in the out-of-plane direction and the (010) diffraction peak in thein-plane direction, which are characteristic of the edge-on orientation of this polymer (Fig.2e). In the in-plane direction, the (010) diffraction peak corresponding to the π-stackingperiodicity (q = 1.73 Å−1) was observed when the incident X-ray and the flow directionduring the circular flow alignment method was parallel, whereas no π-stacking peak wasobserved when the X-ray was perpendicular to the flow direction. The d-spacing in thisdirection had a short value of 3.63 Å. From the width of the (010) diffraction peak, the7paracrystallinity g = 7.6 % was calculated based on the equation g =√12π∆qq: ∆q and q arethe full width at half maximum (FWHM) and peak position of the obtained diffraction peak,respectively. The g value was as small as that of PBTTT (g = 7.3 %),32 which is one of themost crystalline polymeric semiconducting materials.33 In the out-of-plane direction, (h00)diffraction peaks were observed for both parallel and perpendicular incident X-rays to theflow direction with d-spacing of 20.1 Å. These results demonstrate the successful formationof edge-on-oriented, uniaxially aligned thin films with high π-stacking periodicity using ourcircular flow alignment method.Microstructure of Ultrathin FilmsThe PDCBT film morphology was confirmed using atomic force microscopy (AFM, Fig. 3a-d). The spin-coated film possessed isotropically oriented small grains similar to those in aprevious report29,30 (Fig. 3b). The PDCBT thin film prepared by the circular flow alignmentmethod had a fibrous structure with narrow fibers aligned on the micrometer scale (Fig. 3a).The film thickness obtained using the circular flow alignment method was confirmed as ca.8 nm (Fig. S2). The aligned PDCBT film exhibits a smoother surface morphology with aroot mean square (RMS) roughness of 1.06 nm, represented within the black dashed linein Fig. 3c, compared to the spin-coated film (RMS = 2.01 nm). On the surface, steps ofa few nanometers are observed in the magnified image (Fig. 3e), which is consistent withthe calculated lamellar distance (d100 = 20.1 Å) from our X-ray diffraction analysis. Theseresults suggest a highly ordered film structure with clear molecular steps.OFET CharacteristicsImprovements in the carrier transport properties by the circular flow alignment method wereconfirmed by FET measurements. The PDCBT thin films on the liquid surface were trans-ferred onto a Si substrate with a 100 nm SiO2 layer treated with a self-assembled monolayer(SAM). The SAM treatment plays an important role not only in improving FET properties820 nm02468101214161830 nm04681012141618202224262820 nm024681012141618acbd15 nm024681012140.0 0.2 0.4 0.6 0.8 1.0Heightalignedspin-coatede2 nmaligned spin-coatedPosition (µm)1 µm 1 µm1 µm 1 µmFigure 3: AFM images of PDCBT thin films. AFM images of the (a) aligned and (b) spin-coated PDCBT films. Magnified images of the (c) aligned and (d) spin-coated PDCBT films.(e) Height profiles of the aligned and spin-coated PDCBT thin films. The correspondinglocations are shown as white lines in the figure c and d.but also in enabling uniform transfer of the PS films floating on a viscous hydrophilic liq-uid to the target substrate. After transferring the polymer film, the substrate was cleanedwith water to remove the residual glycerol and annealed in a vacuum oven at 175 ◦C for 1h. The Au electrodes were thermally deposited through a shadow mask to fabricate sourceand drain electrodes on the PDCBT thin film. This bottom-gate top-contact FET was thenencapsulated by spin-coating a polymethylmethacrylate (PMMA) thin film. The final devicestructure is shown in Fig. 4a. Fig. 4b shows the output characteristics when the channelis parallel to the flow direction. Fig. 4c and 4d show the linear region with VDS of −3 V9aPMMASourcePDCBTβ-PTS (SAM)  Gate DrainSiO₂ (100 nm)-30-20-10020-2-4-30-20-1001010-60.00.51.01.5-30-20-10001234d-30-20-10010 0.00.20.40.60.81.00 day12 days16 days27 days34 dayse fcb10-710-810-910-10|I DS| (A)|IDS | (µA)VGS (V)|I DS|1/2  (A1/2 )10-310-410-5103 × |IDS | 1/2 (A1/2)VGS (V)VGS:-30 V-25 V-20 V-15 V-10 V-5 V0 VI DS (µA)Time (day)Mobility (cm2 V-1 s-1)10-610-710-810-910-1010-11VGS (V)|I DS| (A)|IDS | (µA)//┴//┴0 10 20 300.00.10.2VDS (V)Figure 4: Characteristic of the fabricated PDCBT transistors. (a) An illustration of thedevice structure. (b) Output, (c) linear, and (d) saturation characteristics of the fabricatedPDCBT transistors. Transistors with channels parallel and perpendicular to the flow di-rection are compared in the linear and saturation characteristics. (e) Linear characteristicsand (f) mobilities measured for a device stored in ambient air. The times stored in air aredenoted as legends. The channel was parallel to the flow direction for this transistor.and the saturation region with VDS of −30 V, respectively, which exhibit a typical p-typetransistor operation. The hole mobility in the PDCBT-based FETs was higher in the direc-tion parallel to the flow direction than in the perpendicular direction, which is reasonableconsidering the alignment of the main chains along the flow direction. The hole mobilityin the linear region was calculated to be 0.13 cm2 V−1 s−1 when the channel was parallel tothe flow direction, which was higher than that of spin-coated PDCBT thin film transistors(µ = 0.03 cm2V−1 s−1) (Fig. S3). Our FET with the channel direction parallel to the flowdirection was measured after storage under dark ambient conditions for up to 34 days. In10these measurements, only slight degradation was observed, which suggests good ambientstability of this device (Fig. 4e). The mobility was almost unchanged during the storage inair (Fig. 4f). Considering that semicrystalline polymers such as P3HT and PBTTT exhibitpoor ambient stability,34,35 PDCBT with the deep HOMO level seems to be suitable forstable operation of devices in air. Above results demonstrate improvement in the mobilityof the ambient stable polymer FET by our method.ConclusionsWe established the circular flow alignment method to fabricate highly aligned edge-on-oriented PS ultrathin films on air-liquid interfaces at room temperature. While the liquidflow has been mostly employed to fabricate one-dimensional fibrous structures, our methodmakes efficient use of liquid flow at the air-liquid interface to fabricate aligned thin filmswith two-dimensional packing structures. The molecular alignment direction was parallel tothe liquid flow, as confirmed by polarized UV-Vis spectroscopy and GIWAXS measurements.The aligned PDCBT thin films exhibited improved mobility along the channel parallel to theflow direction compared to the spin-coated thin film. FET mobility of 0.13 cm2 V−1 s−1 andoperational stability under atmospheric conditions were observed for the aligned thin film.The proposed use of subphase flow will offer an easy way to control the molecular orientationduring the solution process, which has been affected by convection flows during the solventevaporation. In addition, scaling up our method may be feasible by flow path design, whichwill contribute to a wide range of applications of aligned PS thin films.ExperimentalMaterials: PDCBT with an estimated molecular wight of 30-80 kDa was purchased fromSolaris (Lot: 22L400451) and used without any purification. The 0.3 wt% PDCBT solutionwas prepared in a mixture of chloroform and 1-chloronaphthalene at a weight ratio of 9:1. The11solution was maintained at 55◦C on a hotplate and stirred overnight. As a reference, 0.3 wt%PDCBT solution dissolved in o-dichlorobenzene was prepared at 100 ◦C and spin-coated at aspinning speed at 2000 rpm. PBTTT-C14 and PQT-12 were purchased from Sigma-Aldrichand dissolved in o-dichlorobenzene and a mixture of chlorobenzene and 1-chloronaphthaleneat a weight ratio of 9:1. Glycerol (Fujifilm Wako Pure Chemicals) was used as the liquidsubstrate. 1,1,1,3,3,3-Hexamethyldisilazane (HMDS) for self-assembled monolayer (SAM)preparation was purchased from Tokyo chemical industry (TCI) and deposited onto a glasssubstrate for polarized light absorption spectroscopy. 2-(phenylethyl)trimethoxysilane(β-PTS) was also used as SAM for FET device measurement and was purchased from TCI.Poly(methyl methacrylate) (PMMA) with molecular weight of 300kDa was purchased fromPolymer Source.Film Characterization: Polarized UV-vis absorption spectra was obtained using a V-770 (JASCO) equipped with a GPH-506 polarizer. HMDS-treated glass substrates were usedfor optical spectroscopy. Polarized optical microscopy (POM) observations were performedusing a BX-51 (Olympus). Grazing incident wide-angle X-ray scattering (GIWAXS) profilesware recorded on a SmartLab (Rigaku) with a MacroMax-007HF X-ray generator, employingCu Kα radiation (λ = 0.15418 nm).FET Device Fabrication: Heavily doped Si with a 100 nm thermally grown SiO2 layerwas used as the substrate for FETs and the surface was treated with β-PTS. A PDCBTthin film was transferred to the substrate, washed with pure water, and annealed at 175◦Cin vacuum oven for 1h. After annealing, Au electrodes with 40 nm thickness were thermallydeposited through a metal mask to fabricate source/drain electrodes. PMMA was dissolvedin dehydrated butyl acetate at a concentration of 2 wt% and heated on a hot plate at 80◦Cwith constant stirring at 300 rpm over night. The fabricated PDCBT film with Au electrodeswas covered with PMMA encapsulation by spin-coating PMMA solution at 2000 rpm for 1minute. The FET characteristics were all measured by 2634B system sourcemeter (Keithley)in air.12AcknowledgementThis work was supported in part by Japan Society for the Promotion of Science (JSPS)grant-in-aid for scientific research (Kakenhi) (Grant Numbers JP20H00392 and JP23K23428,Japan) and Japan Science and Technology Agency (JST) FOREST Program (Grant NumberJPMJFR236R, Japan).Supporting Information AvailableThe Supporting Information is available free of charge at xxx. Information for GIWAXS,AFM, and FET characteristics of PDCBT thin films and a video of the fabrication process.References(1) Xiao, M.; Ren, X.; Ji, K.; Chung, S.; Shi, X.; Han, J.; Yao, Z.; Tao, X.; Zelewski, S. J.;Nikolka, M.; others Achieving ideal transistor characteristics in conjugated polymersemiconductors. Science Advances 2023, 9, eadg8659.(2) Khim, D.; Luzio, A.; Bonacchini, G. E.; Pace, G.; Lee, M.-J.; Noh, Y.-Y.; Caironi, M.Uniaxial alignment of conjugated polymer films for high-performance organic field-effecttransistors. Advanced Materials 2018, 30, 1705463.(3) Loganathan, K.; Scaccabarozzi, A. D.; Faber, H.; Ferrari, F.; Bizak, Z.; Yengel, E.;Naphade, D. R.; Gedda, M.; He, Q.; Solomeshch, O.; others 14 GHz Schottky DiodesUsing ap-Doped Organic Polymer. Advanced Materials 2022, 34, 2108524.(4) Viola, F. A.; Brigante, B.; Colpani, P.; Dell ’Erba, G.; Mattoli, V.; Natali, D.;Caironi, M. A 13.56 MHz rectifier based on fully inkjet printed organic diodes. Ad-vanced Materials 2020, 32, 2002329.13(5) Hamidi-Sakr, A.; Biniek, L.; Bantignies, J.-L.; Maurin, D.; Herrmann, L.; Leclerc, N.;Lévêque, P.; Vijayakumar, V.; Zimmermann, N.; Brinkmann, M. A Versatile Method toFabricate Highly In-Plane Aligned Conducting Polymer Films with Anisotropic ChargeTransport and Thermoelectric Properties: The Key Role of Alkyl Side Chain Layerson the Doping Mechanism. Advanced Functional Materials 2017, 27, 1700173.(6) Patel, S. N.; Glaudell, A. M.; Peterson, K. A.; Thomas, E. M.; O’Hara, K. A.; Lim, E.;Chabinyc, M. L. Morphology controls the thermoelectric power factor of a doped semi-conducting polymer. Science Advances 2017, 3, e1700434.(7) Biniek, L.; Leclerc, N.; Heiser, T.; Bechara, R.; Brinkmann, M. Large Scale Alignmentand Charge Transport Anisotropy of pBTTT Films Oriented by High TemperatureRubbing. Macromolecules 2013, 46, 4014–4023.(8) Biniek, L.; Pouget, S.; Djurado, D.; Gonthier, E.; Tremel, K.; Kayunkid, N.;Zaborova, E.; Crespo-Monteiro, N.; Boyron, O.; Leclerc, N.; others High-temperaturerubbing: a versatile method to align π-conjugated polymers without alignment sub-strate. Macromolecules 2014, 47, 3871–3879.(9) Shaw, L.; Hayoz, P.; Diao, Y.; Reinspach, J. A.; To, J. W. F.; Toney, M. F.; Weitz, R. T.;Bao, Z. Direct Uniaxial Alignment of a Donor–Acceptor Semiconducting Polymer UsingSingle-Step Solution Shearing. ACS Applied Materials & Interfaces 2016, 8, 9285–9296,PMID: 26985638.(10) Bucella, S. G.; Luzio, A.; Gann, E.; Thomsen, L.; McNeill, C. R.; Pace, G.; Perinot, A.;Chen, Z.; Facchetti, A.; Caironi, M. Macroscopic and high-throughput printing ofaligned nanostructured polymer semiconductors for MHz large-area electronics. NatureCommunications 2015, 6, 8394.(11) Khim, D.; Han, H.; Baeg, K.-J.; Kim, J.; Kwak, S.-W.; Kim, D.-Y.; Noh, Y.-Y. Simple14bar-coating process for large-area, high-performance organic field-effect transistors andambipolar complementary integrated circuits. Advanced Materials 2013, 25, 4302–4308.(12) Gu, X.; Shaw, L.; Gu, K.; Toney, M. F.; Bao, Z. The meniscus-guided deposition ofsemiconducting polymers. Nature Communications 2018, 9, 534.(13) Ito, M.; Yamashita, Y.; Tsuneda, Y.; Mori, T.; Takeya, J.; Watanabe, S.; Ariga, K.100 °C-Langmuir-Blodgett Method for Fabricating Highly Oriented, Ultrathin Filmsof Polymeric Semiconductors. ACS Applied Materials & Interfaces 2020, 12, 56522–56529.(14) Morita, T.; Singh, V.; Nagamatsu, S.; Oku, S.; Takashima, W.; Kaneto, K. Enhance-ment of Transport Characteristics in Poly(3-hexylthiophene) Films Deposited withFloating Film Transfer Method. Applied Physics Express 2009, 2, 111502.(15) Pandey, M.; Pandey, S. S.; Nagamatsu, S.; Hayase, S.; Takashima, W. Solvent drivenperformance in thin floating-films of PBTTT for organic field effect transistor: Role ofmacroscopic orientation. Organic Electronics 2017, 43, 240–246.(16) Jana, S.; Pandey, R. K.; Prakash, R. Evolution of Edge-On Oriented Polymer FilmsSelf-Assembled at the Air-Liquid Interface for High-Performance Electronic Device Ap-plications. ACS Applied Polymer Materials 2022, 4, 4818–4828.(17) Pandey, M.; Sugita, Y.; Toyoda, J.; Katao, S.; Abe, R.; Cho, Y.; Benten, H.; Naka-mura, M. Unidirectionally Aligned Donor-Acceptor Semiconducting Polymers in Float-ing Films for High-Performance Unipolar n-Channel Organic Transistors. AdvancedElectronic Materials 2023, 9, 2201043.(18) Sharma, S.; Vats, A. K.; Tang, L.; Kaishan, F.; Toyoda, J.; Nagamatsu, S.; Ando, Y.;Tamagawa, M.; Tanaka, H.; Pandey, M.; Pandey, S. S. High field-effect mobility in ori-ented thin films of D-A type semiconducting polymers by engineering stable interfacialsystem. Chemical Engineering Journal 2023, 469, 143932.15(19) Yamashita, Y.; Hinkel, F.; Marszalek, T.; Zajaczkowski, W.; Pisula, W.; Baum-garten, M.; Matsui, H.; Müllen, K.; Takeya, J. Mobility Exceeding 10 cm2/(V·s) inDonor-Acceptor Polymer Transistors with Band-like Charge Transport. Chemistry ofMaterials 2016, 28, 420–424.(20) Ito, M.; Yamashita, Y.; Mori, T.; Ariga, K.; Takeya, J.; Watanabe, S. Band mobilityexceeding 10 cm2 V- 1 s- 1 assessed by field-effect and chemical double doping insemicrystalline polymeric semiconductors. Applied Physics Letters 2021, 119 .(21) Zhang, S.; Koziol, K. K.; Kinloch, I. A.; Windle, A. H. Macroscopic fibers of well-alignedcarbon nanotubes by wet spinning. Small 2008, 4, 1217–1222.(22) Jalili, R.; Razal, J. M.; Innis, P. C.; Wallace, G. G. One-step wet-spinning processof poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonate) fibers and the origin ofhigher electrical conductivity. Advanced Functional Materials 2011, 21, 3363–3370.(23) Gantenbein, S.; Masania, K.; Woigk, W.; Sesseg, J. P.; Tervoort, T. A.; Studart, A. R.Three-dimensional printing of hierarchical liquid-crystal-polymer structures. Nature2018, 561, 226–230.(24) Herbert, K. M.; Fowler, H. E.; McCracken, J. M.; Schlafmann, K. R.; Koch, J. A.;White, T. J. Synthesis and alignment of liquid crystalline elastomers. Nature ReviewsMaterials 2022, 7, 23–38.(25) Zhu, S.; Wang, S.; Huang, Y.; Tang, Q.; Fu, T.; Su, R.; Fan, C.; Xia, S.; Lee, P. S.;Lin, Y. Bioinspired structural hydrogels with highly ordered hierarchical orientationsby flow-induced alignment of nanofibrils. Nature Communications 2024, 15, 118.(26) McCulloch, I.; Heeney, M.; Bailey, C.; Genevicius, K.; MacDonald, I.; Shkunov, M.;Sparrowe, D.; Tierney, S.; Wagner, R.; Zhang, W.; others Liquid-crystalline semicon-ducting polymers with high charge-carrier mobility. Nature Materials 2006, 5, 328–333.16(27) Zhang, M.; Guo, X.; Ma, W.; Ade, H.; Hou, J. A Polythiophene Derivative with SuperiorProperties for Practical Application in Polymer Solar Cells. Advanced Materials 2014,26, 5880–5885.(28) Wang, Q.; Li, M.; Zhang, X.; Qin, Y.; Wang, J.; Zhang, J.; Hou, J.; Janssen, R. A. J.;Geng, Y. Carboxylate-Substituted Polythiophenes for Efficient Fullerene-Free PolymerSolar Cells: The Effect of Chlorination on Their Properties. Macromolecules 2019, 52,4464–4474.(29) Lee, Y. W.; Pak, K.; Park, S. Y.; An, N. G.; Lee, J.; Kim, J. Y.; Woo, H. Y. Regioiso-meric Polythiophene Derivatives: Synthesis and Structure-Property Relationships forOrganic Electronic Devices. Macromolecular Research 2020, 28, 772–781.(30) Wu, Y.-S.; Lin, Y.-C.; Hung, S.-Y.; Chen, C.-K.; Chiang, Y.-C.; Chueh, C.-C.; Chen, W.-C. Investigation of the Mobility-Stretchability Relationship of Ester-Substituted Polythiophene Derivatives. Macromolecules 2020, 53, 4968–4981.(31) Oliveira Jr, O. N.; Caseli, L.; Ariga, K. The past and the future of Langmuir andLangmuir–Blodgett films. Chemical reviews 2022, 122, 6459–6513.(32) Rivnay, J.; Noriega, R.; Kline, R. J.; Salleo, A.; Toney, M. F. Quantitative analysis oflattice disorder and crystallite size in organic semiconductor thin films. Phys. Rev. B2011, 84, 045203.(33) Noriega, R.; Rivnay, J.; Vandewal, K.; Koch, F. P. V.; Stingelin, P., Natalie adn Smith;Toney, M. F.; Salleo, A. A general relationship between disorder, aggregation and chargetransport in conjugated polymers. Nature Materials 2013, 12, 1038–1044.(34) Ong, B. S.; Wu, Y.; Liu, P.; Gardner, S. High-Performance Semiconducting Polythio-phenes for Organic Thin-Film Transistors. Journal of the American Chemical Society2004, 126, 3378–3379, PMID: 15025437.17(35) McCulloch, I. et al. Semiconducting Thienothiophene Copolymers: Design, Synthesis,Morphology, and Performance in Thin-Film Organic Transistors. Advanced Materials2009, 21, 1091–1109.18