Nucleation and Growth of P(NDI2OD-T2) Nanowires via Side Chain Ordering and Backbone Planarization

Zhao, Kai; Zhang, Qiang; Liang, Changhao; Zhang, Tao; Han, Yanchun

doi:10.1021/acs.macromol.0c02436

Cited by 41 publications

(58 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We can see from above that TDPP-Se polymers with different M n showed distinct differences in microstructure and thus device performance of bar-and spin-coated films. Therefore, considering that the solution-state structure plays an important role in determining the solid-state microstructure, [37,38,42,49] we surmise that the polymers with various molecular weights may have different impacts on the polymer aggregation structures in solution and thus differing device performance. Accordingly, SANS measurements on o-DCB-d 4 solution and TEM measurements on freeze-dried samples were performed to explore the effect of M n on solution-state aggregation and thus provide some useful insights in precisely controlling the aligned structure for realizing high-performance OTFTs.…”

Section: Resultsmentioning

confidence: 99%

Unraveling the Molar Mass Dependence of Shearing‐Induced Aggregation Structure of a High‐Mobility Polymer Semiconductor

Wang

Gao

et al. 2022

Advanced Materials

View full text Add to dashboard Cite

Aggregation‐structure formation of conjugated polymers is a fundamental problem in the field of organic electronics and remains poorly understood. Herein, the molar mass dependence of the aggregation structure of a high‐mobility conjugated copolymer (TDPP‐Se) comprising thiophene‐flanked diketopyrrolopyrrole and selenophene is thoroughly shown. Five batches of TDPP‐Se are prepared with the number‐average molecular weights (Mn) varied greatly from 21 to 135 kg mol−1. Small‐angle neutron scattering and transmission electron microscopy are combined to probe the solution structure of these polymers, consistently using a deuterated solvent. All the polymers adopt 1D rod‐like aggregation structures and the radius of the 1D rods is not sensitive to the Mn, while the length increases monotonically with Mn. By utilizing the ordered packing of the aggregated structure in solution, a highly aligned and ordered film is prepared and, thereafter, a reliable hole mobility of 13.8 cm2 V−1 s−1 is realized in organic thin‐film transistors with the moderate Mn batch via bar coating. The hole mobility is among the highest values reported for diketopyrrolopyrrole‐based polymers. This work paves the way to visualize the real aggregated structure of polymer semiconductors in solution and sheds light on the microstructure control of high‐performance electronic devices.

show abstract

Section: Resultsmentioning

confidence: 99%

Unraveling the Molar Mass Dependence of Shearing‐Induced Aggregation Structure of a High‐Mobility Polymer Semiconductor

Wang

Gao

et al. 2022

Advanced Materials

View full text Add to dashboard Cite

show abstract

“…10 nm in width. 34,38 High-resolution transmission electron microscopy (HRTEM) reveals a remarkable order at the chain level in P(NDI2OD-T2) films cast from dichlorobenzene solution. 39 The effect of molecular weight on the crystalline behavior and electrical properties of P(NDI2OD-T2) has been investigated by several studies.…”

Section: ■ Introductionmentioning

confidence: 99%

Role of Molecular Weight in Microstructural Transition and Its Correlation to the Mechanical and Electrical Properties of P(NDI2OD-T2) Thin Films

Zhao

Zhang

et al. 2021

Macromolecules

Self Cite

View full text Add to dashboard Cite

Semiconducting polymers with high mobility and mechanical robust properties are strongly dependent on their molecular weight. However, the relationship between molecular weights and solution chain entanglements, film microstructures, charge carrier mobility, and mechanical properties for donor−acceptor conjugated polymers remains less understood. Herein, P(NDI2OD-T2) with a weight-average molecular weight (M w ) from 34.0 to 280 kDa was investigated as a model system. The polymer chain exhibited three regions in chloroform solutions: fewer entanglements (34.0−77.7 kDa), enhanced entanglements (170 kDa), and severe entanglements (280 kDa). This chain solution behavior resulted in three distinct film microstructures: (1) 34.0−77.7 kDa, liquid-crystalline-like morphologies with highly ordered chain arrangements and large crystallite lengths (l c ) yet relatively low tie-chain densities that increased with M w ; (2) 170 kDa, small fibril morphology with less ordered chain arrangements and a decreased l c of only 5.6 nm yet a high tie-chain density; and (3) 280 kDa, a seemingly amorphous film with vast wellconnected local aggregates embedded in an entangled network. The structural change in films significantly affected the electrical and mechanical performances. The electron mobility increased continuously with M w , correlating well with the tie-chain density. By contrast, the crack-onset strain was less than 3% at 34.0−77.7 kDa and then jumped to 36.4 ± 0.9 and 60.4 ± 2.1% for 170 and 280 kDa, showing a close correlation with the solution entanglement density, which could be inherited into films. This study contributes to structural development of rigid chains with M w and demonstrates that the microstructure containing vast well-connected local aggregates and adequate entanglements is promising toward mechanically robust semiconducting films.

show abstract

“…The contrasting chemical structures of the aromatic backbone and the aliphatic side chain of PII-2T (Figure 1a) offers a possibility to dissolve the polymer into various solvents that exhibit either selective solubility to one or mutual solubility for both the backbone and the side chain. The solvent selectivity has been shown to have significant impact on the solutionstate structure and assembly of conjugated polymers 32,33 . In this work, we choose seven common organic solvents shown in Figure 1a to tune the solution-state structure and classify them into three categories based on their selective nature: (i) a backbone solvent 1chloronaphthalene (CN) with an aromatic naphthalene ring substituted with a halogen atom, (ii) a side chain solvent decane with a saturated aliphatic structure, and (iii) solvents mutually dissolving backbone and side chain with a benzene ring with varied substituents, including 1,2,4-trichlorobenzene (TCB), 1,2-dichlorobenzene (DCB), chlorobenzene (CB), tetralin and toluene.…”

Section: Resultsmentioning

confidence: 99%

“…CN solution gives a sharp lamellar stacking peak with a full width at half maximum (FWHM) around 0.02 Å -1 , indicating a highly ordered packing of side chains at RT. It is suggested that such a strong lamellar packing can reduce solvophobic interactions between the aliphatic side chain and solvent, which further results in backbone planarization to give highly anisotropic aggregates 33 . Such an ordered lamellar packing is disrupted by heating, evidenced by the significant broadening of the SAXS lamellar stacking peak at temperature above 115 °C (Figure S5b).…”

Section: Resultsmentioning

confidence: 99%

Not all aggregates are made the same: Distinct structures of solution aggregates drastically modulate assembly pathways, morphology and electronic properties of conjugated polymers

Park

Kwok

et al. 2022

Preprint

View full text Add to dashboard Cite

Tuning structures of solution-state aggregation and aggregation-mediated assembly pathways of conjugated polymers is crucial for optimizing their solid-state morphology and charge transport property. However, it remains challenging to unravel and control the exact structures of solution aggregates, let alone to modulate assembly pathways in a controlled fashion. Herein, we largely modulate aggregate structures by tuning selectivity of the solvent towards the side chain vs. the backbone, which leads to three distinct assembly pathways: direct crystallization from side-chain associated amorphous aggregates, chiral liquid crystal (LC)-mediated assembly from semicrystalline aggregates with side-chain and backbone stacking, random agglomeration from backbone-stacked semicrystalline aggregates. Importantly, we demonstrate for the first time that the amorphous solution aggregates, compared with semicrystalline ones, lead to significantly improved alignment and reduced paracrystalline disorder in solid-state due to direct crystallization during the meniscus-guided coating process. Alignment quantified by dichroic ratio obtained from grazing incidence X-ray diffraction (GIXD) is enhanced by up to fourteen-fold, and the charge carrier mobility increases by a maximum of twenty-fold in films printed from amorphous aggregates compared to those from semicrystalline aggregates. This work shows that by tuning the precise structure of solution aggregates, one can drastically tune assembly pathways, and the resulting thin film morphology and device properties.

show abstract

Nucleation and Growth of P(NDI2OD-T2) Nanowires via Side Chain Ordering and Backbone Planarization

Cited by 41 publications

References 45 publications

Unraveling the Molar Mass Dependence of Shearing‐Induced Aggregation Structure of a High‐Mobility Polymer Semiconductor

Unraveling the Molar Mass Dependence of Shearing‐Induced Aggregation Structure of a High‐Mobility Polymer Semiconductor

Role of Molecular Weight in Microstructural Transition and Its Correlation to the Mechanical and Electrical Properties of P(NDI2OD-T2) Thin Films

Not all aggregates are made the same: Distinct structures of solution aggregates drastically modulate assembly pathways, morphology and electronic properties of conjugated polymers

Contact Info

Product

Resources

About