Subscriber access provided by UB + Fachbibliothek Chemie | (FU-Bibliothekssystem)
Article
Construction of Electron Transfer Network by SelfAssembly of Self-n-Doped Fullerene Ammonium Iodide Xuan Sun, Weiwei Chen, Lijun Liang, Wei Hu, Huanhuan Wang, Zhenfeng Pang, Yuxun Ye, Xiurong Hu, Qi Wang, Xueqian Kong, Yizheng Jin, and Ming Lei Chem. Mater., Just Accepted Manuscript • DOI: 10.1021/acs.chemmater.6b04056 • Publication Date (Web): 16 Nov 2016 Downloaded from http://pubs.acs.org on November 20, 2016
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Chemistry of Materials is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 7
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Chemistry of Materials
Construction of Electron Transfer Network by Self-Assembly of Selfn-Doped Fullerene Ammonium Iodide Xuan Sun,† Weiwei Chen,† Lijun Liang,§ Wei Hu,‖ Huanhuan Wang,† Zhenfeng Pang,† Yuxun Ye,† Xiurong Hu,† Qi Wang,† Xueqian Kong,† Yizheng Jin,† and Ming Lei*,† † Department of Chemistry, Zhejiang University, Hangzhou 310027, China § College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China ‖Division of Theoretical Chemistry and Biology, School of Biotechnology, KTH Royal Institute of Technology, SE-10691 Stockholm, Sweden ABSTRACT: Construction of π-conjugation network in ordered fullerenes by self-assembly remains challenging for improving their optoelectronic performance and developing advanced materials. Here, we present a layered stacking of self-n-doped fullerene ammonium iodide (PCBANI) through a delicate balance among iodide anion–C60 π, electrostatic, and C60 π–π interactions to construct an unprecedented supramolecular system. XRD, TEM, SEM, XPS, and computational modeling are carried out to clarify the structure. Remarkably, the formation of intermolecular iodide anion–π interactions between iodide and the surrounded fullerene cores yields an iodide linked C60 π–π 2D network. Consequently the ordered and tightly packed fullerenes sandwiching iodide could facilitate electron transfer along the network system. Comparative devices incorporating the disordered films show dramatically decreased current densities and manifest the importance of the π–extended network for electron transfer. This work provides a key strategy to control the packing of ordered electron-transport materials to suppress defect formation. Moreover, engineering self-assembly of self-n-doped fullerenes with novel architectures such as nanowire, nanotube, and nanoparticle would yield new functionalities that are suitable for photovoltaic devices, nanoelectronics, etc.
INTRODUCTION Owing to their unique spherical and π–conjugated electronic structure, carefully manipulating fullerenes (C60 and its derivatives) self-assembly through selective interactions and solvents for construction of various functional nanostructures could provide excellent properties and functions. It’s well know that non-covalent interactions involving hydrogen bonding, π–π interaction, electrostatic effects, van der Waals force, and metal-coordination are commonly used individually or jointly to develop self-assembled (self-organized) nanostructures.1-12 Moreover, engineering architectures with controllable dimensionality and morphology at the molecular level by modifying individual fullerene building block have attracted considerable interest for development of optoelectronics,13–16 liquid crystals,17-21 and other functional materials.22,23 Despite of the increasing interest in self-assembly of fullerenes, introducing non-covalent interactions and precisely fine-tuning the π–π interaction to endow fullerenes with favorable electronic properties remain challenging for improving their optoelectronic performance and developing advanced assembled materials. Doping with iodide is a major factor in the development of conducting materials in organic electronics.24 Recently, highly conductive fullerene ammonium iodides (σ = 1–2 S/m) have emerged as a new generation of electron-transport layer (ETL) materials for solar cells and enable large-area device fabrication possible.25–28 Our previous study manifested that partial electron transfer from iodide to core fullerene could result in
n-doping and high conductivity. We proposed cross self-ndoping mechanism in fullerene ammonium iodide (PCBANI, Scheme 1) at the molecular level and believe that in PCBANI film, the iodide sandwiched in fullerene core acts as a shuttle to transfer electrons via redox processes (Figure 1) 29. This model indicates that the construction of extended π– conjugation network of ordered fullerene core linked by iodide dopant would benefit effective electron transfer. O
Cation-π interaction
N
O
N O
PCBAN
O δ¯
MeI O
N
I
δ¯
PCBANI
O
Cross self-n-doping I Anion-π interaction
Scheme 1. Molecular structural of self-n-doped PCBANI.
Figure 1. Proposed electron transfer model for PCBANI.
ACS Paragon Plus Environment
Chemistry of Materials
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
It is noteworthy that the doping effect in PCBANI causes separation of cation–anion pair in the ammonium salt building block and yields dipolarized fullerene species. We envision that the increased polarization in molecule enhances the energy and PCBANIs tend to selfassemble to achieve stability since fullerene core, iodide anion, and nitrogen cation are available for formation of non-covalent interactions. Herein, we present a new lamellar self-assembly of PCBANI by solvent dispersion and reorganization of its disordered pristine powder. This unprecedented self-assembly is driven by iodide anion– C60 π, electrostatic, and intermolecular C60 π–π triple noncovalent interactions, in which the iodide anion–C60 π interaction is crucial to form an iodide linked C60 π–π network. The self-assembly of PCBANI forms ordered and tightly packed fullerene arrangement sandwiching iodide and exhibits a much better electron transfer property than its disordered counterpart.
Page 2 of 7
1.0 nm, respectively. These values of the lamellar periodicity taken from the TEM images are in good agreement with the bilayer thickness and space between neighboring fullerene cores obtained from the XRD analysis. The distance between adjacent fullerenes (1.0 nm) suggests a strong C60 π–π interaction8,21 and relative highly ordered alignment of fullerene cores. Moreover, field-emission scanning electron microscopy (FESEM) images reveal that the disordered and loose sheet-like aggregates are formed in PCBANI pristine powder (Figure 4a). Moreover, the self-assembled PCBANI appears to be solid and indicates tight packing into highly ordered domains in uniform thin films over large areas (Figure 4b and Figure 4c).
RESULTS AND DISCUSSION Firstly, X-ray diffraction (XRD) was employed to analyze the PCBANI pristine powder obtained from methylation of its precursor (PCBAN, Scheme 1)29 in chloroform after centrifugation and decanting. As shown in Figure 2a, the weak peak with d-spacing value of 2.90 nm in the diffraction pattern indicates the existence of short-range ordered arrangement in the disordered aggregates. It seems that chloroform is a poor solvent for assembly. Then we try to reorganize this aggregate in DMSO. Remarkably, the spin-coated film (~5 µm) from DMSO dispersion of the above pristine powder exhibits well-defined XRD pattern, which is attributed to the Bragg reflections from (001) to (005) planes with a lamellar periodicity d-spacing value of 2.90 nm (Figure 2b). This value corresponds to the length of a bilayer with a little interdigitation, given that the lateral dimension of PCBANI is approximately 1.56 nm as obtained from quantum mechanics calculations.29 Moreover, a strong peak overlapped with the (003) plane peak at 2θ ≈ 9.2°, which corresponds to 0.96 nm distance, presumably caused by neighboring fullerene cores.8,21 In addition, a broad halo centered at 2θ ≈ 22° (marked with black dot) is assigned to PCBANI’s characteristic peak. Therefore, the XRD analysis indicates ordered multilayer alignment of PCBANI. Reviewing Figure 2a, the appearance of weak peak with d-spacing value of 2.90 nm suggests that chloroform is not favorable for long-range assembly thus forms aggregates. While, DMSO is helpful for reorganizing short-range self-assemblies and realizing long-range assembly. To further understand the nature of architecture, the above PCBANI samples are dispersed in ethanol by extensive sonication, and then subjected to high-resolution transmission electron microscopy (HR-TEM) analysis to obtain bright-field imaging (Figure 3). In Figure 3a, the image and corresponding Fast Fourier transform (FFT) analysis show that the pristine powder appears to be a porous disordered aggregate. While, cross-sectional HRTEM on the above self-assembled sample unambiguously reveal a well-developed lamellar structure in these systems (Figure 3b and Figure 3c). FFT analysis of the lamellar parts of the image yield periodicities of 3.0 nm and
Figure 2. XRD pattern of PCBANI. (a) Pristine powder and (b) Spin-coated film from DMSO dispersion of pristine powder. Neighboring fullerene cores peak overlapped with the (003) plane peak at 2θ ≈ 9.2° in the insert.
To clarify the interactions that govern the assembly, Xray photoelectron spectroscopy (XPS) survey is used to probe the electronic structure of the related elements in PCBANI pristine powder and self-assembled film. In Figure 5a, for the iodide in self-assembled PCBANI film, the binding energy increases by 2.60 eV for I 3d3/2 and I 3d5/2 peaks compared with that in its pristine powder. Meanwhile, the binding energy decreases by 3.50 eV for N1s peaks and 0.50 eV for C1s peaks in self-assembled PCBANI film versus that in its pristine powder (Figure 5b and Figure 5c). These changes in electronic structure of the relevant elements imply this self-assembly is obtained through a delicate balance among iodide C60 π–π, iodide anion–π, and anion-cation electrostatic interaction both in intra- and intermolecular aspect and results in tight packing of PCBANIs.
ACS Paragon Plus Environment
Page 3 of 7
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Chemistry of Materials
Figure 3. HR-TEM image of PCBANI. (a) Pristine powder with porous disordered structure. (b),(c) Cross-sectional images of self-assembled PCBANI with lamellar structures and corresponding FFT analysis. The periodicities of the lamellae are 3.0 nm and 1.0 nm, respectively. A large area image of the lamellae with 3.0 nm periodicity is shown in Figure S1.
Figure 4. FESEM images of PCBANI. (a) Pristine powder with disordered array. (b) Self-assembled PCBANI appears to be solid and tightly packed. (c) Self-assembled PCBANI with lamellar structures.
Figure 5. XPS spectra of PCBANI’s pristine powder in comparison to its self-assembled film. (a) I 3d3/2 and I 3d5/2; (b) N1s; and (c) C 1s. The binding energy scale was calibrated using the C 1s line (284.6 eV) from the carbon contamination.
These results undoubtedly demonstrate the selfassembly of PCBANI and the supramolecular structure is illustrated in Figure 6. We further performed a firstprinciple calculation for the PCBANI assembling structure with periodic boundary condition (PBC) model by using VASP (the Vienna ab initio simulation package).30 The projector augmented wave pseudopotentials were employed to represent the interaction between the core ions and the valence electrons.31 The exchange-correlation effects were described by the Perdew-Burke-Ernzerhof (PBE) generalized-gradient approximation32 with a plane wave basis. The cutoff of the basis set was set to be 400 eV. The DFT-D3 method was used to evaluate the vdW energy.33 The optimized Xview, Y-view, and Z-view structures (Figure 7a-7c) show that the distance between fullerene cores is 0.95 nm, and it is ca. 2.90 nm in the two layers which agrees with XRD and TEM results. Especially, the Z-view image presents a vivid iodide linked C60 π–π 2-D network structure (Figure
7c ).
C60 π-π Interaction
Anion-π Interaction
Figure 6. Schematic representation of the structure of selfassembled PCNANI driven by triple non-covalent interactions.
ACS Paragon Plus Environment
Chemistry of Materials
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
(a)
(b)
Page 4 of 7
(c)
2.90nm
0.95nm
2.90nm
0.95nm 0.95nm
0.95nm
Figure 7. Optimized structure of self-assembled PCNANI obtained from computational modelling. (a) X-view. (b) Y-view. (c) Z-view.
Our previous work elucidated cross n-doping effect in PCBANI which causes separation of the loose cation– anion pair in the ammonium salt moiety. Concomitantly, ammonium ion accesses the aromatic ring face to stabilize through weak cation–π interactions. We believe the increased polarization in molecule enhances the energy of PCBANI, and then intrinsically actuates supramolecular self-assembly to achieve stability. Compared with chloroform, DMSO is good solvent to disperse and reorganize PCBANI to form long range assembly. In this structure, the ammonium cations have access to iodides in the upper PCBANI layer to form electrostatic interactions, resulting in disappearance of weak cation–π interaction, as demonstrated by solid-state NMR (Figure S2). In conjunction with intermolecular anion–π and C60 π–π interactions, triple interactions attribute to stabilization of self-n-doped PCBANI and oriented self assembly in a supramolecular manner. To the best of our knowledge, this study presents the first example of self-assembly of fullerene derivative in which a delicate balance among anion–π, electrostatic, and intermolecular C60 π–π interactions results in a unique layered mesocrystalline structure. Strikingly, the formation of intermolecular iodide anion–π interactions between iodide and the surrounded fullerene cores yields an iodide linked C60 π–π 2-D network. It is clear that the supramolecular arrangement of conjugated molecules significantly affect the optoelectronic properties.4,34-38 As an n-type electron transport material, self-organized structures wherein iodide linked C60 π–π network with long-range order is crucial to electron transport. By using electron-only device method, we compared the electron transport property of the well-ordered and tightly-packed PCBANI film with that of the disordered film obtained by thermal annealing (XRD pattern and AFM are shown in Figure S3). As shown in Figure 8, under the film thickness at 230 and 150 nm, both of the self-assembled PCBANI film exhibit much higher current densities than that of the corresponding disordered film in the same voltage range (0–3 V), respectively. In addition, the improvement of
current density in thinner film suggests that it exhibits thickness sensitivity. These results demonstrate that selfassembly via non-covalent interactions is a key strategy to control the packing of ordered electron-transport materials and to suppress defect formation, namely, iodide in the assembled structure prevents the formation of deep interfullerene electron traps.39 In PCBANI film, closed-packed and ordered assembly of iodide-doped fullerene could extend π-conjugation to enhance its charge transfer property. In addition, this film with unique self-assembled structure would yield functions such as blocking interfacial layer to enhance device stability of perovskite solar cells.40
Figure 8. J–V characteristics of the electron-only devices with the structure ITO/PCBANI/Al. PCBANI film thickness is 230nm for (a) with enlarged figure in the insert and 150 nm for (b).
ACS Paragon Plus Environment
Page 5 of 7
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Chemistry of Materials
CONCLUSIONS
ter operating at a resonance frequency of 400.13 MHz for H, 100.62 MHz for 13C, using MAS probes equipped with 3.2mm spinner modules at spinning speed of 15KHz. Cross-polarization (CP) contact time is 500µs for the experiments. The magic angle and field homogeneity of the spectrometer were optimized using KBr and adamantine at room temperature, respectively. Fabrication of electron-only device. The electron-only devices ITO/PCBANI (230 nm, with or without thermal annealing) /Al (100nm) were used. ITO-coated glass substrates were cleaned sequentially with detergent aqueous solution, acetone, deionized water, and absolute ethyl alcohol, each for 10 min. The cleaned substrates were then treated with air plasma for 10 min. After that, the PCBANI DMSO solution (200mg/mL) was directly spincoated onto the ITO substrates at 3000 rpm for 3 min inside a glove box filled with nitrogen and then half of them were thermally annealed at 120°C for 20 min. Finally, the devices were completed after deposition of 100nm Al as the electrode. 1
In conclusion, we present a self-assembly of PCBANI with 2-D lamellar architectures through a delicate balance among anion–π, electrostatic, and intermolecular C60 π–π interactions. By introducing of iodide anion–π interaction, this self-assembly constructs an iodide linked C60 π–π network to facilitate charge transfer. Our work discloses the intrinsic self-assembly property of self-n-doped fullerene ammonium salt which could yield new functionalities that are suitable for photovoltaic devices, nanoelectronics, etc. Therefore, studies on the extended functionalized architectures such as nanowire, nanotube, and nanoparticle are being conducted. At same time, molecular dynamics simulations for thermodynamic and dynamic studies on self-assembly of PCBANI are in progress to semiquantificationally explain the stability of self n-doped fullerenes.
Experimental section Materials. All solvents were purchased from Sinopharm Chemical Reagent Co. Ltd. and PCBM from PCBAN was synthesized in accordance with literature method.24 X-ray diffraction (XRD). XRD patterns were measured at room temperature using a RIGAKU D/MAX 2550/PC X-ray diffractometer with monochromatic Cu Kα radiation (λ = 1.54184 Å) at 18 kW. Scanning electron microscopy (SEM). The morphologies of the films were examined with a HITACHI SU 8010 SEM at 1-10kV. Glass was used as a substrate and a platinum coating was performed using a MCI1000 ion sputter. High resolution transmission electron microscopy (HRTEM). HR-TEM images were obtained with a JEM2100F microscope. One drop of a dispersion with absolute ethyl alcohol of the objects was deposited on a carbon-coated copper grid (230 mesh), the excess solution on the grid was drained off with a filter paper, left to dry, and then observation was performed at room temperature of 200 kV (HR-TEM). The HR-TEM image of the edge-on lamellar morphology was observed from a microtome section (50 nm-thick) conducted on an ultramicrotome (Leica EM UC7). X-ray photoelectron spectroscopy (XPS). XPS Measurements of the samples were carried out in a Thermo Scientific ESCALAB 250Xi spectrometer. All spectra were taken using a monochromatic Al Kα (1486.8 eV) Xray radiation at 180W. The typical operating pressure was 2×10–7 Pa. The binding energy scale was calibrated using the C 1s line (284.6 eV) from the carbon contamination. Atomic force microscopy (AFM). AFM images were carried out on a Bruker-Dimension Edge Atomic Force Microscope under tapping mode in air. To prepare the sample, PCBANI solution was spin-coated on a glass substrate at 3000rmp for 3 min. Solid state NMR (ssNMR). 13C-1H HetCor spectra were acquired on a Bruker Avance III HD 400MHz spectrome-
ASSOCIATED CONTENT Supporting Information. XRD pattern and AFM for disordered PCBANI film (Figure S1-S3). This material is available free of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION Corresponding Author *E-mail:
[email protected] Funding Sources National Nature Science Foundation of China (No. 21442005, 21573197).
Notes The authors declare no competing financial interest.
ACKNOWLEDGMENT This work was supported by National Nature Science Foundation of China (No. 21442005, 21573197). We thank Dr. Q. H. He, Mrs. F. Chen, and Dr. X. K. Ding for their help in TEM and SEM measurements. We thank Prof. D. Y. Chen from Department of Macromolecular Science in Fudan University for his help in manuscript preparation. We thank Prof. H. Y. Li from Department of Polymer Science and Engineering in Zhejiang University for his helpful discussion.
REFERENCES (1) Babu, S. S.; Möhwald, H.; Nakanishi, T. Recent Progress in Morphology Control of Supramolecular Fullerene Assemblies and Its Applications. Chem. Soc. Rev. 2010, 39, 4021–4035. (2) Nakanishi, T. Supramolecular Soft and Hard Materials Based on Self-Assembly Algorithms of Alkyl-Conjugated Fullerenes. Chem. Commun., 2010, 46, 3425–3436. (3) Shen, Y. F.; Nakanishi, T. Fullerene Assemblies toward PhotoEnergy Conversions. Phys. Chem. Chem. Phys. 2014, 16, 7199–7204. (4) Li, C. Z.; Yip, H. -L.; Jen, A. K.-Y. Functional Fullerenes for Organic Photovoltaics. J. Mater. Chem. 2012, 22, 4161–4177. (5) Guldi, D. M.; Martín, N. Fullerene Architectures Made to Order; Biomimetic Motifs-Design and Features. J. Mater. Chem. 2002, 12, 1978–1992. (6) Sánchez, L.; Martín, N.; Guldi, D. M. Hydrogen-Bonding Motifs in Fullerene Chemistry. Angew. Chem. Int. Ed. 2005, 44, 5374–5382.
ACS Paragon Plus Environment
Chemistry of Materials
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
(7) Yan, W. B.; Seifermann, S. M.; Pierrat, P.; Bräse, S. Synthesis of Highly Functionalized C60 Fullerene Derivatives and Their Applications in Material and Life Sciences. Org. Biomol. Chem. 2015, 13, 25–54. (8) Sato, S.; Takei, T.; Matsushita, Y.; Yasuda, T.; Kojima, T.; Kawano, M.; Ohnuma, M.; Tashiro, K. Coassembly-Directed Fabrication of an Exfoliated Form of Alternating Multilayers Composed of a Selfassembled Organoplatinum(II) Complex–Fullerene Dyad. Inorg. Chem. 2015, 54, 11581–11583. (9) A. M. Cassell, C. L. Asplund, J. M. Tour, Self-Assembling Supramolecular Nanostructures from a C60 Derivative: Nanorods and Vesicles. Angew. Chem. Int. Ed. 1998, 38, 2403–2405. (10) Kim, K.; Lee, T. H.; Santos, E, J. G.; Jo, P. S.; Salleo, A.; Nishi, Y.; Bao, Z. N. Structural and Electrical Investigation of C60-Graphene Vertical Heterostructures. ACS Nano 2015, 9, 5922–5928. (11) Kim, J.; Park, C.; Park, J. E.; Chu, K.; Choi, H. C. Vertical Crystallization of C60 Nanowires by Solvent Vapor Annealing Process. ACS Nano 2013, 7, 9122–9128. (12) Shrestha, L. K.; Yamauchi, Y.; Hill, J. P.; Miyazawa, K. Ariga, K. Fullerene Crystals with Bimodal Pore Architectures Consisting of Macropores and Mesopores. J. Am. Chem. Soc. 2013, 135, 586–589. (13) Nakanishi, T.; Shen, Y. F.; Wang, J. B.; Yagai, S.; Funahashi, M.; Kato, T.; Fernandes, P.; Möhwald, H.; Kurth, D. G. Electron Transport and Electrochemistry of Mesomorphic Fullerenes with Long-Range Ordered Lamellae. J. Am. Chem. Soc. 2008, 130, 9236– 9237. (14) Chu, C.-C.; Raffy, G.; Ray, D.; Guerzo, A. D.; Kauffmann, B.; Wantz, G.; Hirsch, L.; Bassani, D. M. Self-Assembly of Supramolecular Fullerene Ribbons via Hydrogen–Bonding Interactions and Their Impact on Fullerene Electronic Interactions and Charge Carrier Mobility. J. Am. Chem. Soc. 2010, 132, 12717–12723. (15) Ma, D.; Lv, M. L.; Lei, M.; Zhu, J.; Wang, H. Q.; Chen, X. W. Self-Organization of Amine-Based Cathode Interfacial Materials in Inverted Polymer Solar Cells. ACS Nano 2014, 8, 1601–1608. (16) Zhang, J. Y.; Li, C. Z.; Williams, S. T.; Liu, S. Q.; Zhao, T.; Jen, A. K. -Y. Crystalline Co-Assemblies of Functional Fullerenes in Methanol with Enhanced Charge Transport. J. Am. Chem. Soc. 2015, 137, 2167–2170. (17) Murakami, H.; Watanabi,Y.; Nakashima, N. Fullerene Lipid Chemistry: Self-Organized Multibilayer Films of a C60-Bearing Lipid with Main and Subphase Transitions. J. Am. Chem. Soc. 1998, 118, 4484–4485. (18) Sawamura, M.; Kawai, K.; Matsuo, Y.; Kaine, K.; Kato, T.; Nakamura, E. Stacking of Conical Molecules With a Fullerene Apex into Polar Columns in Crystals and Liquid Crystals. Nature 2002, 419, 702–705. (19) Zhang, X.; Hsu, C.-H.; Ren, X.; Gu, Y.; Song, B.; Sun, H.-J.; Yang, S.; Chen, E.; Tu, Y.; Li, X.; Yang, X.; Li, Y.; Zhu, X. Supramolecular [60]Fullerene Liquid Crystals Formed by Self-Organized Two-Dimensional Crystals. Angew. Chem., Int. Ed. 2015, 54, 114– 117. (20) Li, H. G.; Hollamby, M. J.; Seki,T.; Yagai, S. Möhwald, H.; Nakanishi, T. Multifunctional, Polymorphic, Ionic Fullerene Supramolecular Materials: Self-Assembly and Thermotropic Properties. Langmuir 2011, 27, 7493–7501. (21) Hollamby, M. J.; Karny, M.; Bomans, P. H. H.; Sommerdijk, N. A. J. M.; Saeki, A.; Seki, S.; Minamikawa, H.; Grillo, I.; Pauw1, B. R.; Brown, P.; Eastoe, J.; Möhwald, H.; Nakanishi, T. Directed Assembly of Optoelectronically Active Alkyl-π-Conjugated Molecules by Adding n-Alkanes or π-Conjugated Species. Nature Chem. 2014, 6, 690–696. (22) Minar, N. K.; Hou, K.; Westermeier, C.; Döblinger, M.; Schuster, J.; Hanusch, F. C.; Nickel, B. Ozin, G. A.; Bein, T. A HighlyOrdered 3D Covalent Fullerene Framework. Angew. Chem. Int. Ed. 2015, 54, 7577–7581. (23) Nakanishi, T.; Michinobu, T.; Yoshida, K.; Shirahata, N.; Ariga, K.; Möhwald, H.; Kurth, D. G. Nanocarbon Superhydrophobic Surfaces Created from Fullerene-Based Hierarchical Supramolecular
Page 6 of 7
Assemblies. Adv. Mater. 2008, 20, 443–446. (24) Lüssem, B.; Keum, C.-M.; Kasemann, D.; Naab, B.; Bao, Z. N.; Leo K. Doped Organic Transistors. Chem. Rev. DOI: 10.1021/acs.chemrev.6b00329. (25) Li, S. S.; Lei, M.; Lv, M. L.; Watkins, S. E.; Tan, Z. A.; Zhu, J.; Hou, J. H.; Chen, X. W.; Li, Y. F. Self n-Doped [6,6]-Phenyl-C61Butyric Acid 2-((2-(Trimethylammonium)Ethyl)(Dimethyl)Ammonium)Ethyl Ester Diiodides as a Cathode Interlayer for Inverted Polymer Solar Cells. Adv. Energy Mater. 2013, 23, 1569–1574. (26) Jiao, W. X.; Ma, D.; Lv, M. L.; Chen, W. W.; Wang, H. Q.; Zhu, J.; Lei, M.; Chen, X. W. Self n-Doped [6,6]-Phenyl-C61-Butyric Acid 2-((2-(Trimethylammonium)Ethyl)(Dimethyl)-Ammonium)ethyl Ester Diiodides as a Cathode Interlayer for Inverted Polymer Solar Cells. J. Mater. Chem. A 2014, 2, 14720–14728. (27) Li, C. Z.; Chueh, C. C.; Yip, H. L.; O’Malley, K. M.; Chen, W. C.; Jen, A. K.-Y. J. Mater. Chem. Effective Interfacial Layer to Enhance Efficiency of Polymer Solar Cells via Solution-Processed Fullerene-Surfactants. 2012, 22, 8574–8578. (28) O’Malley, K. M.; Li, C. Z.; Yip, H. L.; Jen, A. K.-Y. Enhanced Open-Circuit Voltage in High Performance Polymer/Fullerene BulkHeterojunction Solar Cells by Cathode Modification with a C60 Surfactant. Adv. Energy Mater. 2012, 2, 82–86. (29) Chen, W. W.; Jiao, W. X.; Li, D. B.; Sun, X.; Guo, X.; Lei, M.; Wang, Q.; Li, Y. F. Cross Self-n-Doping and Electron Transfer Model in a Stable and Highly Conductive Fullerene Ammonium Iodide: A Promising Cathode Interlayer in Organic Solar Cells. Chem. Mater. 2016, 28, 1227–1235. (30) Kresse, G.; Furthmüller, J. Efficient Iterative Schemes for ab Initio Total-Energy Calculations Using A Plane-Wave Basis Set. Phys. Rev. B 1996, 54, 11169–11186. (31) Blöch, P. E. Projector Augmented-Wave Method. Phys. Rev. B 1994, 50, 17953–17979. (32) Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized Gradient Approximation Made Simple. Phys. Rev. Lett. 1996, 77, 3865–3868. (33) Grimme, S.; Ehrlich, S.; Goerigk, L. Effect of the Damping Function in Dispersion Corrected Density Functional Theory. J. Comp. Chem. 2011, 32, 1456–1465. (34) Coropceanu, V.; Cornil, J.; Da Silva Filho D. A.; Olivier, Y.; Silbey, R.; Brédas, J.-L. Charge Transport in Organic Semiconductors. Chem. Rev. 2007, 107, 926–952. (35) O’Neill, M.; Kelly, S. M. Ordered Materials for Organic Electronics and Photonics. Adv. Mater. 2011, 23, 566–584. (36) Tummala, N. R.; Elroby, S. A.; Aziz, S. G.; Risko, C.; Coropceanu, V. Packing and Disorder in Substituted Fullerenes. J. Phys. Chem. C 2016, 120, 17242–17250. (37) Ryno, S. M.; Risko, C.; Brédas, J.-L. Impact of Molecular Packing on Electronic Polarization in Organic Crystals: The Case of Pentacene vs TIPS-Pentacene. J. Am. Chem. Soc. 2015, 137, 6421–6427. (38) Sutton, C.; Risko, C.; Brédas, J.-L. Noncovalent Intermolecular Interactions in Organic Electronic Materials: Implications for the Molecular Packing vs Electronic Properties of Acenes. Chem. Mater. 2016, 28, 3–16. (39) Shubina, T. E.; Sharapa, D. I.; Schubert, C.; Zahn, D.; Halik, M.; Keller, P. A.; Pyne, S. G.; Jennepalli, S.; Guldi, D. M.; Clark, T. Fullerene Van der Waals Oligomers as Electron Traps. J. Am. Chem. Soc. 2014, 136, 10890–10893. (40) Berhe, T. A.; Su, W.-N.; Chen, C.-H.; Pan, C.-J.; Cheng, J.-H.; Chen, H.-M.; Tsai, M.-C.; Chen, L.-Y.; Dubale, A. A.; Hwang, B.-J. Organometal Halide Perovskite Solar Cells: Degradation and Stability. Energy Environ. Sci. 2016, 9, 323–356.
ACS Paragon Plus Environment
Page 7 of 7
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Chemistry of Materials
Construction of Electron Transfer Network by Self-Assembly of Self-n-Doped Fullerene Ammonium Iodide
C60 π-π Interaction
Anion-π Interaction
ACS Paragon Plus Environment
