Depth-Resolved Characterization of Perylenediimide Side-Chain

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Depth-Resolved Characterization of Perylenediimide Side-Chain Polymer Thin Film Structure Using GrazingIncidence Wide-Angle X-ray Diffraction with Tender X-ray Kazutaka Kamitani, Ayumi Hamada, Kazutoshi Yokomachi, Kakeru Ninomiya, Kiyu Uno, Masaru Mukai, Yuko Konishi, Noboru Ohta, Maiko Nishibori, Tomoyasu Hirai, and Atsushi Takahara Langmuir, Just Accepted Manuscript • DOI: 10.1021/acs.langmuir.8b01566 • Publication Date (Web): 27 Jun 2018 Downloaded from http://pubs.acs.org on July 3, 2018

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Depth-Resolved Characterization of Perylenediimide Side-Chain Polymer Thin Film Structure Using Grazing-Incidence Wide-Angle X-ray Diffraction with Tender X-ray Kazutaka Kamitani†, Ayumi Hamada†, Kazutoshi Yokomachi†, Kakeru Ninomiya♯, Kiyu Uno‖, Masaru Mukai†, Yuko Konishi†, Noboru Ohta‡, Maiko Nishibori¶, Tomoyasu Hirai*†,§, ⊥, Atsushi Takahara*†,§, ⊥ †

Institute for Materials Chemistry and Engineering, ‖Graduate School of Engineering, and

§

International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu

University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan ‡

Japan Synchrotron Radiation Research Institute/SPring-8, Sayo, Hyogo, 679-5198, Japan

¶

Faculty of Energy and Material Sciences and ♯Interdisciplinary Graduate School of

Engineering Science, Kyushu University, 6-1 Kasugakoen, Kasuga, Fukuoka 816-8580, Japan ⊥

Research Center for Synchrotron Light Applications, Kyushu University, 6-1 Kasugakoen,

Kasuga, Fukuoka 816-8580, Japan

ACS Paragon Plus Environment

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KEYWORDS: Tender X-ray, Depth Profile, Grazing-Incidence Wide-Angle X-ray Diffraction, Crystalline Structure.

ABSTRACT: Polymers with perylenediimide (PDI) side chain (PAc12PDI) consist of two kinds of crystalline structures with various types of orientations in a thin film. Understanding the population of the microcrystalline structure and its orientation along the thickness is strongly desired. Grazing-incidence wide-angle X-ray diffraction (GIWAXD) measurements with hard Xray, which is generally chosen as 0.1 nm, are a powerful tool to evaluate the molecular aggregation structure in thin films. A depth-resolved analysis for the outermost surface of the polymeric materials using conventional GIWAXD measurements, however, has limitations because the X-ray penetration depth dramatically increases above the critical angle. Meanwhile, tender X-ray (λ = 0.5 nm) has the potential advantage that the penetration depth gradually increases above the critical angle, leading to precise characterization for the population of crystallite distribution along the thickness. The population of the microcrystalline structure in the PAc12PDI thin film was precisely characterized utilizing GIWAXD measurements using tender X-ray. The outermost surface of the PAc12PDI thin film is occupied by a monoclinic lattice with a = 2.38 nm, b = 0.74 nm, c = 5.98 nm, and β = 108.13°, while maintaining the c-axis perpendicular to the substrate surface. Additionally, the presence of solid substrate controls the formation of the crystalline structure with unidirectional orientation.


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INTRODUCTION Organic semiconducting materials have significant potential as flexible, low-cost, and easily processable alternatives to silicon-based semiconducting materials.1 Recently, several p- and ntype polymeric materials that consist of crystalline2,

3

or liquid crystalline domains4,

5

have

emerged as potential candidates. Hitherto, the relation between the molecular aggregation state and

functional

properties

in

polymer

thin

films

has

been

investigated

using

cyclopentadithiophenebenzothiadiaxole copolymer dip-coating film, whose primary chain was oriented parallel to the coating direction, and anisotropy between the conjugated and π-stacking direction was observed6. Control over the orientation of the microcrystalline structure was also achieved using self-assembled monolayers, and the effect of the microcrystalline structure orientation on the performance was investigated7. However, in general, the molecular aggregation state on the outermost surface of polymer thin films is different compared to that in the bulk8, 9. Although understanding the relations between these molecular aggregation states on the outermost surface and the functional properties of the film is crucial for developing highly efficient semiconducting polymeric materials, precise characterization methods along the film thickness are limited. Polymers with perylenediimide (PDI) pendant side chains, which show the crystalline structure in thin films, are of great interest as n-type semiconducting materials.10, 11, 12, 13 The electronic conducting properties are strongly related to the crystalline structure of PDI moieties in the polymer. Hitherto, we have reported the preparation of a polymer with PDI-designated PAc12PDI that formed various kinds of crystalline structures with different orientation axes in the thin film state, depending on the sample preparation condition and molecular weight of the polymers14,

15

. Moreover, the formation of the crystalline structure strongly affects the


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performance of the memory properties. To understand the essential properties of the PAc12PDI thin films, the population of the microcrystalline structure along the thickness is strongly desired14. However, the gradient of the crystalline state and the crystallite orientation on the outermost surface and buried interface have not been clearly understood because of the limitation of the measurement methods. Surface analytical measurements including grazing-incidence wide-angle X-ray diffraction (GIWAXD),16 X-ray photoelectron spectroscopy,17,

18

time-of-flight secondary ion

mass spectrometry,19, 20 and neutron reflectivity21 are widely utilized in various fields. Among them, GIWAXD has the advantage of determining the distribution of not only the ordered structures but also the buried interfaces in thin films along the thickness direction.22 Meanwhile, the refractive index of polymeric materials is generally higher than that of air, and for X-rays the value is slightly lower than that of air. Subsequently, the evanescent wave is generated when the X-ray beam is irradiated from the air to the polymer surface below the critical angle, αc. This allows a precise structural characterization at the polymer/air interface. Conventional GIWAXD measurements often use hard X-ray with a wavelength of 0.1 nm (12.4 keV) to evaluate the molecular aggregation states in polymer thin films.23, 24, 25 However, this method could not be used to obtain the precise characterization of the outermost surface or depth profiling along the thickness direction, because the penetration depth of hard X-ray slightly above αc is too large to evaluate the surface structures. In contrast, the penetration depth of tender X-ray, which has a wavelength of 0.25–0.62 nm (2–5 keV), is more precisely controlled by the change in incident angle (αi) compared to hard X-ray. This allows the accurate characterization of molecular aggregation states on the surface by changing the incident angle.26, 27, 28 Hitherto, the grazing incidence of small-angle X-ray scattering with tender X-ray has been applied for the


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characterization of microphase-separated nanostructures in block copolymer thin films, and the precise characterization along the thickness has been achieved. Meanwhile, GIWAXD with tender X-ray has not been applied for the characterization of microstructures in polymer thin films. In this study, we first employed GIWAXD with tender X-ray to understand the depth profile of crystalline states in the thin films of polymer with PDI side chains.


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Figure 1. a) Chemical structure of PAc12PDI. b) Schematic diagram of GIWAXD geometry, where 2θz and 2θxy are Bragg angle and c) X-ray penetration depth profiles of PAc12PDI thin film using hard X-ray (0.1 nm) and tender X-ray (0.5 nm). EXPERIMENTAL SECTION Materials All chemicals were used without any purification. PAc12PDI, whose molecular structure is shown in Figure 1a, was prepared using the same method as previously reported.14, 15 The PAc12PDI was purified based on re-precipitation. The primary structure was characterized based on the 1H and 13C nuclear magnetic resonance spectra. The molecular weight (Mn) was evaluated using size exclusion chromatography. In this experiment, we used silicon (111) wafers with their native oxide layer, whose diameter was 25 mm. PAc12PDI thin films were prepared by spincoating 5 wt% dichlorobenzene solution on the silicon wafers. The films were annealed at 483 K for 10 min and subsequently annealed at 463 K for 12 h. The film thickness was evaluated using spectroscopic ellipsometry (MASS-103FH system, Five lab.). The value was determined based on the average of five measurements. The film thickness was 69±1.2 nm.

Measurements GIWAXD measurements with hard and tender X-ray were performed at BL40B2 in SPring-8 and at Kyushu University Beam Line (BL06) in the Kyushu Synchrotron Light Research Center (Saga, Japan), respectively. The detector for the hard X-ray (λ = 0.1 nm) was an imaging plate (IP) with the dimensions of 300 mm × 300 mm and a pixel size of 100 µm × 100 µm, while the detector model for the tender X-ray (λ = 0.5 nm) was PILATUS3 300K (83.8 mm × 106.5 mm with a pixel size of 172 µm × 172 µm). The sample-to-detector lengths for the two GIWAXD


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experiments were 833.2 mm and 341.6 mm, respectively. Figure 1b shows the geometry of the GIWAXD measurements. When the X-ray is irradiated to the thin films below the critical angle (αc), an evanescent wave was generated. The diffraction along the in-plane caused by the evanescent wave was observed on the 2θxy direction, while the diffraction along the out-of-plane can be observed on the 2θz direction. The scattering vector (q) was calculated based on q = (4π/λ)sinθ, where 2θ is the Bragg angle. The ranges of q for the IP along the meridional and equatorial axes are both 11 nm-1, while those for PILATUS are 3.2 nm-1 along the equatorial axis and 3.7 nm-1 along the meridional axis. Generally, the photon flux of the tender X-ray decays in the atmosphere because of absorption by nitrogen and oxygen molecules; therefore, it is unable to pass air with a 20 mm path length. Hence, the GIWAXD measurements with tender X-ray (λ = 0.5 nm) were performed in a helium atmosphere, while those with hard X-ray (λ = 0.1 nm) were performed in an air atmosphere. The penetration depth (Λ) of the X-ray is estimated using equations 1 and 2,29

Λ =

= /2

!

∑$ #$ %$" '/ ∑$ #$ ($

(1) (2)

where re, NA, ρM, wz, Az, f’’z(E), and αc are the classical electron radius (2.82 × 10-5 Å), Avogadro’s number, density of the polymer, atomic fraction, relative atomic mass of element Z, and the imaginary part of the anomalous scattering factor, respectively. The values of the imaginary part of the anomalous scattering factor in carbon were 0.115092 (0.5 nm) and 3.60382×10-3 (0.1 nm). Meanwhile, the values for the imaginary part of the anomalous scattering


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factor of hydrogen, nitrogen, and oxygen were 1.95099×10-5 (0.5nm), 3.89176×10-7 (0.1 nm), 0.211656 (0.5nm), 7.02685×10-3 (0.1 nm), 0.364239 (0.5nm), and 1.31147×10-2 (0.1 nm), respectively. Here, the ρM of PAc12PDI was evaluated to be 1.14 g/cm3 using a density gradient column with potassium iodide solution at 293 K, and the references were o-dichlorobenzene (1.305 g/cm3), benzotrifluoride (1.19 g/cm3), 1-bromohexane (1.176 g/cm3), chlorobenzene (1.107 g/cm3), 1-bromononane (1.090 g/cm3), and 1-bromoundecane (1.054 g/cm3). We assumed that the density in the polymer thin film is constant. We also assumed a constant intensity for the X-ray penetrating the polymer thin film, although this value decays to 1/e when αi is set to higher than the polymer’s critical angle. The penetration depth was plotted against the incidence angle αi in Figure 1c. In the GIWAXD measurements with hard X-ray (λ = 0.1 nm), αi was set to 0.08° or 0.12°, while for the tender X-ray (λ = 0.5 nm) measurements, it was changed from 0.2° to 0.6° in steps of 0.05°. The footprint size for the hard X-ray (λ = 0.1 nm) ranged from 107 mm (αi = 0.08°) to 71 mm (αi = 0.12°), and from 43 mm (αi = 0.2°) to 14 mm (αi = 0.6°) for the tender X-ray (λ = 0.5 nm). The Λ value was 4.3 µm and 11 nm when αi was set to 0.12° and 0.08°, respectively, in the measurements with hard X-ray (λ = 0.1 nm), while it was 4, 8, 11, 25, 50, and 120 nm when αi = 0.20°, 0.40°, 0.45°, 0.50°, 0.55°, and 0.60°, respectively, using tender X-ray (λ = 0.5 nm). The wettability of the PAc12PDI films against water was evaluated based on static and dynamic contact angle measurements, performed at 296 K using a Theta T-200 system (Auto3, Altech Co., Ltd.) using a water droplet as the probe. For the static contact angle measurement, 1

µL of water droplet was used, while the dynamic contact angle was measured using the liquid expansion–contraction method at a 0.25 µL/s flow rate.


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RESULTS AND DISCUSSION Figure 1c shows the relation between the αi and X-ray penetration depth in the PAc12PDI thin film, calculated from equations 1 and 2. When using hard X-ray (λ = 0.1 nm) for the GIWAXD measurements, the penetration depth suddenly changed at approximately αi = 0.08°. In the case of tender X-ray (λ = 0.5 nm), the change in Λ is much smaller and slower in comparison, leading to the precise characterization of the outermost surface in the thin film. PAc12PDI (Mn = 8,000) was spin coated and annealed as described in section 2, before the films were characterized using GIWAXD measurements with hard and tender X-ray. Figure 2a shows the GIWAXD pattern with hard X-ray (λ = 0.1 nm) using αi = 0.12°, which is higher than the critical angle of PAc12PDI and lower than that of the substrate. All diffraction patterns were clearly assigned by assuming two kinds of monoclinic crystal types (designated Types 1 and 2) with various orientations.12,13 The crystal parameters of Type 1 are as follows: a = 2.38 nm, b = 0.74 nm, c = 5.98 nm, and β = 108.13°; while those for Type 2 are a = 2.38 nm, b = 0.74 nm, c = 6.00 nm, and β = 71.23°. Panels (I)–(VI) in Figure 2c schematically show these monoclinic lattices with different orientations, in which the panels (I), (III), and (V) consist of Type-1 crystalline lattice, and panels (II), (IV), and (VI) are formed by Type-2 crystalline lattice. The critical angle of the PAc12PDI film is 0.11 when hard X-ray was irradiated. By considering Figure 1c, the molecular aggregation states in the thin film from the surface to down to approximately 10 nm can be evaluated using GIWAXD with hard X-ray (λ = 0.1 nm), with αi of 0.08°.


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Figure 2. 2D GIWAXD patterns of PAc12PDI film with hard X-ray (λ = 0.1 nm) at a) αi = 0.12° and b) 0.08°. c) Two kinds of crystalline lattices with different orientations. (I), (III), and (V) are of Type 1; while (II), (IV), and (VI) are of Type 2.


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Figure 2b shows the GIWAXD patterns of the PAc12PDI film with hard X-ray (λ = 0.1 nm) using αi = 0.08°. Diffraction spots corresponding to the (001), (002), and (003) planes are observed along the meridional axis on qxy = 0 nm-1. The diffraction assigned to the (001) plane are observed in both the (I) and (II) structures, as shown in Figure 2c. Hence, we cannot assign it to either (I) or (II). The diffraction assigned to the (1*01), (100), (1*02), and (101) planes is also observed along the meridional axis on qxy = 2.64 nm-1. This indicates that both the (I) and (II) structures were present in the film. Moreover, the diffraction corresponding to the (002) plane is observed along the meridian axis on qxy = 2.11 nm-1. This diffraction spot is shown in both (III) and (IV). Although the diffraction assigned to the (1*02) plane cannot be observed along the meridian axis on qxy = 2.11 nm-1, the (100) diffraction is shown along the meridional axis on qxy = 0 nm-1. This indicates that the (IV) structure did not exist in the film. By considering these results, it is clear that (I), (II), and (III) were present in the PAc12PDI thin film from the surface down to approximately 10 nm deep. To evaluate the crystalline structure in the surface region, GIWAXD measurements with tender X-ray (λ = 0.5 nm) were performed. Figure 3a shows the patterns obtained at αi = 0.20°, 0.40°, 0.45°, 0.50°, 0.55°, and 0.60°, with the respective penetration depths of approximately 4, 8, 11, 25, 50, and 120 nm. The data at αi = 0.20° show two diffraction spots, which could be assigned to the (002) and (003) planes. Moreover, specific diffraction spots corresponding to the (001), (100), and (101) planes, which can only be assigned to (I) as shown in Figure 2c, were observed when αi was set to 0.40°. This indicates that only (I) was formed in the region from the outermost surface down to approximately 8 nm. When αi = 0.45, the (001), (002), (100), and (003) planes are observed along the meridional axis on qxy = 0 nm-1. The (002) plane also appears along the meridional axis on qxy = 2.11 nm-1. The diffraction spots assigned to (100) and


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(101) appear along the meridional axis on qxy = 2.64 nm-1, indicating that (I) and (III) were formed at approximately the surface range down to 11 nm on the outermost surface region. Here, the penetration depth using hard and tender X-ray (αi = 0.08° and 0.45°, respectively) are comparable. However, the experimental results are different. The penetration depth for the tender X-ray gradually increased with increasing αi, where it dramatically changed with αi above αc when using hard X-ray. Hence, a much more precise control of αi is necessary for depth profiling by GIWAXD with hard X-ray. However, controlling αi to within two decimal precision is technically difficult, leading to a deeper penetration depth than that we did not expect. The diffraction spots corresponding to (1*01), (1*02), and (1*03), which are attributed to the formation of (II), started to appear when αi = 0.50°. The diffraction spots corresponding to (IV), (V), and (VI) are observed when αi = 0.55°. These indicate that all crystalline structures with different orientations, which are shown in the hard X-ray (λ = 0.1 nm) with αi of 0.12°, start to appear at approximately the 50 nm deep region. To directly evaluate the population of the microcrystalline structures with different orientations, the line profiles along the meridional axis on qxy = 2.11 nm1

and 2.64 nm-1, and the equatorial axis on qz = 2.11 nm-1 were evaluated (Figure 3b–d). The

solid line is the best-fit curve using the Gaussian function (equation 3),

+, - = +./0 ∗ 234 −

6

7

8 = 3, : ;
D

+, ?2-|A8B ?|C?, 8 = 1 ; 2

(4)

The obtained I1(q) and I2(q) were converted to the populations of (I) and (VI), respectively. The population of the crystalline structure and the orientation axis in the PAc12PDI films from


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the outermost surface down to the substrate is summarized in Table 1. It is clear that (I) encompasses the outermost surface of the film. Moreover, the ratio between Type 1 and Type 2 in the film evaluated at αi= 0.6° was 7:3. Recently, we evaluated the crystalline structure in the PAc12PDI fiber sample and found that only Type 1 existed.14 By considering these results, Type 1 might be easier to form than Type 2 under our experimental conditions. To confirm the surface chemical structure, static and dynamic contact angle measurements were performed using pure water as the probe. In the literature, the surface chemical structure of various kinds of selfassembled monolayers (SAM) of alkyls with long chains has been evaluated using contact angle measurements. When the layer is in the amorphous state, the static contact angle is approximately 100°, while the dynamic contact angle of the advancing and receding are approximately 100° and 90°, respectively. In this study, the measured static contact angle was 93.4±2.5°, while the dynamic advancing and receding contact angles were 103.5±1.5° and 88±2.3°, respectively. These values showed good agreement with those of SAM.31 Therefore, it is clear that the hydrophobic alkyl tails in PAc12PDI are segregated on the outermost surface to minimize the surface free energy,6 leading to the preferential formation of state (I). Meanwhile, the substrate suppresses the formation of state (I), resulting in the formation of two kinds of crystalline structures with various kinds of orientations.


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Figure 3. a) 2D GIWAXD patterns of PAc12PDI film with tender X-ray (λ = 0.5 nm) at given αi values, b) GI-WAXD line profiles along the meridional axis at qxy = 2.64 nm-1 and c) at qxy = 2.11 nm-1. d) Line profiles along the equatorial axis at qz = 2.11 nm-1. e) Azimuth profile of the (002) diffraction corresponding to π–π interaction. The open symbols in (b–e) are the experimental data, the red solid lines are the best-fit curves. Table 1. Population of each microcrystalline structure (see Figure 2b) at a given αi. Incidence angle ° / Penetration depth nm

(I) / %

(II) / %

(III) / %

(IV) / %

(V) / %

(VI) / %

0.2° / 4 nm

100

0.0

0.0

0.0

0.0

0.0

0.4° / 8 nm

100

0.0

0.0

0.0

0.0

0.0

0.45° / 11 nm

93.6

0.0

6.4

0.0

0.0

0.0

0.5° / 25 nm

84.3

1.9

13.8

0.0

0.0

0.0

0.55° / 50 nm

56.1

2.9

3.5

0.7

26.4

10.5

0.6° / 120 nm

17.8

1.0

2.4

0.8

49.6

28.4


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CONCLUSIONS The PAc12PDI thin film formed two kinds microcrystalline structures, called type 1: a = 2.38 nm, b = 0.74 nm, c = 5.98 nm, β = 109.13°, and type 2: a = 2.38 nm, b = 0.74 nm, c = 6.00 nm, β = 71.23°, which consisted of three kinds of orientations. We have successfully characterized these populations of microcrystalline structures in the PAc12PDI films along the thickness using new GIWAXD measurements with tender X-ray. The outermost surface was covered by structure (I) to minimize the surface free energy. Meanwhile, the silicon substrate regulates the formation of only the preferable state (I), leading to a mixed crystalline structure of Type 1 and Type 2 with different orientations. This new GIWAXD technique using tender X-ray can be applied to depth-resolved characterizations of crystalline polymer thin films, thus leading to the development of high-performance organic solar cells and organic field-effect transistors.


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ASSOCIATED CONTENT Supporting Information: The Supporting Information is available free of charge on the ACS Publications website. The sample damage from the tender X-ray at this experimental condition (PDF). AUTHOR INFORMATION Present Address: Tomoyasu Hirai is in Department of Applied Chemistry, Osaka Institute of Technology, 5-16-1 Ohmiya, Asahi-ku, Osaka, 535-8585, Japan. Corresponding Authors *Tomoyasu Hirai. Telephone: +81-66-167-5125. Email: [email protected]. *Atsushi

Takahara.

Telephone:

+81-92-802-2517.

Fax:

+81-92-802-2518.

Email:

[email protected].

ACKNOWLEDGMENTS This work was supported by Photon and Quantum Basic Research Coordinated Development Program from the Ministry of Education, Culture, Sports, Science, and Technology, Japan. We also acknowledge support from the World Premier International Research Center Initiative (WPI) MEXT, Japan, and the Cooperative Research Program of “Network Joint Research Center for Materials and Devices.” Part of this work was supported by the Impulsing Paradigm Change through Disruptive Technologies (ImPACT) Program. This work was performed under the Cooperative Research Program of "Network Joint Research Center for Materials and Devices.” The X-ray diffraction measurements were performed at the BL02B2 and BL40B2 beam lines of SPring-8 under the proposal numbers 2014B1285 and 2016B1227. GIWAXD experiments using tender X-ray were performed at the Kyushu University Beam line in SAGA-LS.


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REFERENCES (1) Yang, X.; Ed.; Semiconducting Polymer Composites: Principles, Morphologies, Properties and Applications. Wiley-VCH Verlag GmbH & Co. KGaA: 2012. (2) Gregg, B. A.; Evolution of Photophysical and Photovoltaic Properties of Perylene Bis(phenethylimide) Films upon Solvent Vapor Annealing. J. Phys. Chem. 1996, 100, 852-859. (3) Sirringhaus, H.; Brown, P. J.; Friend, R. H.; Nielsen, M. M.; Bechgaard, K.; LangeveldVoss, B. M. W.; Spiering, A. J. H.; Janssen, R. A. J.; Meijer, E. W.; Herwig, P.; de Leeuw, D. M. Two-Dimensional Charge Transport in Self-Organized, High-Mobility Conjugated Polymers. Nature 1999, 401, 685-688. (4) Xu, Y. J.; Leng, S. W.; Xue, C. M.; Sun, R. K.; Pan, J.; Ford, J.; Jin, S. A RoomTemperature Liquid-Crystalline Phase with Crystalline π stacks. Angew. Chem. Int. Ed. 2007, 46, 3896-3899. (5) Struijk, C. W.; Sieval, A. B.; Dakhorst, J. E. J.; van Dijk, M.; Kimkes, P.; Koehorst, R. B. M.; Donker, H.; Schaafsma, T. J.; Picken, S. J.; van de Craats, A. M.; Warman, J. M.; Zuilhof, H.; Sudholter, E. J. R. Liquid Crystalline Perylene Diimides: Architecture and Charge Carrier Mobilities. J. Am. Chem. Soc. 2000, 122, 11057-11066. (6) Tsao, H. N.; Cho, D.; Andreasen, J. W.; Rouhanipour, A.; Breiby, D. W.; Pisula, W.; Mullen, K. The Influence of Morphology on High-Performance Polymer Field-Effect Transistors. Adv. Mater. 2009, 21, 209-212. (7) Kline, R. J.; McGehee, M. D.; Toney, M. F. Highly Oriented Crystals at the Buried Interface in Polythiophene Thin-Film Transistors. Nat. Mater. 2006, 5, 222-228.


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(15) Kido, M.; Nojima, S.; Ishige, R.; White, K. L.; Kamitani, K.; Ohta, N.; Hirai, T.; Takahara, A. Effect of Molecular Weight on Microcrystalline Structure Formation in Polymer with Perylenediimide Side Chain. J. Polym. Sci. Pol. Phys. 2016, 54, 2275-2283. (16) Yakabe, H.; Sasaki, S.; Sakata, O.; Takahara, A.; Kajiyama, T. Paracrystalline Lattice Distortion in the Near-Surface Region of Melt-Crystallized Polyethylene Films Evaluated by Synchrotron-Sourced Grazing-Incidence X-ray Diffraction. Macromolecules 2003, 36, 59055907. (17) Helmer, J. C.; Weichert, N. H. Enhancement of Sensitivity in ESCA Spectrometers. Appl. Phys. Lett. 1968, 13, 266-268. (18) Ikenaga, E.; Kobata, M.; Matsuda, H.; Sugiyama, T.; Daimon, H.; Kobayashi, K. Development of High Lateral and Wide Angle Resolved Hard X-ray Photoemission Spectroscopy at BL47XU in SPring-8. J. Electron. Spectrosc. Relat. Phenom. 2013, 190, 180187. (19) Ninomiya, S.; Ichiki, K.; Yamada, H.; Nakata, Y.; Seki, T.; Aoki, T.; Matsuo, J. Precise and Fast Secondary Ion Mass Spectrometry Depth Profiling of Polymer Materials with Large Ar Cluster Ion Beams. Rapid Commun. Mass Spectrom. 2009, 23, 1601-1606. (20) Takahara, A.; Kawaguchi, D.; Tanaka, K.; Tozu, M.; Hoshi, T.; Kajiyama, T. Analysis of Surface Composition of Isotopic Polymer Blend Based on Time-of-Flight Secondary Ion Mass Spectroscopy. Appl. Surf. Sci. 2003, 203, 538-540. (21) Mayes, A. M.; Russell, T. P.; Bassereau, P.; Baker, S. M.; Smith, G. S. Evolution of Order in Thin Block-Copolymer Films. Macromolecules 1994, 27, 749-755.


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SYNOPSIS

“For Table of Contents use only” Depth-Resolved Characterization of Perylenediimide Side-Chain Polymer Thin Film Using Grazing-Incidence Wide-Angle X-ray Diffraction with Tender X-ray Kazutaka Kamitani, Ayumi Hamada, Kazutoshi Yokomachi, Kakeru Ninomiya, Kiyu Uno, Masaru Mukai, Yuko Konishi, Noboru Ohta, Maiko Nishibori, Tomoyasu Hirai, Atsushi Takahara


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Depth-Resolved Characterization of Perylenediimide Side-Chain

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