Precrystalline P3HT nanowires: growth-controllable solution processing and effective molecular packing transfer to thin film

Abstract

Solution-processable precrystalline nanowires (NWs) of conjugated polymers (CPs) have garnered significant attention in fundamental research based on crystallization-driven self-assembly and in the roll-to-roll fabrication of optoelectronic devices such as organic...

Fluorinated Alcohol-Processed N-Type Organic Electrochemical Transistor with High Performance and Enhanced Stability

“…Compared with an almost 1:1 ratio of edge-on and face-on orientations for gNR-CF , the films cast from FAs show crystallites with a very high ratio of edge-on orientations, 94.8, 86.3, and 84.2% for gNR-6FOH , gNR-3FOH , and gNR-9FOH , respectively. Therefore, the predominance of edge-on orientation and tighter molecular packing for FA cast films are conducive to the effective charge transport in the parallel direction of the device architecture. , To gain insight into the crystallinity difference of gNR in thin films, coherence lengths (CLs) and paracrystalline disorder ( g ) were calculated from the width of the π–π stacking diffraction peaks (CL = 2π K /FWHM, K = 0.9, ). , As shown in Figure S16c, the gNR thin films formed with FAs displayed further enhanced crystalline packing: the CL values of the (010) peaks along the IP direction increased from 47.9 Å for CF to 59.5 Å for 3FOH, 71.5 Å for 6FOH, and 54.9 Å for 9FOH. Meanwhile, the CLs of the emerging (020) peak were also calculated to be 60.8 Å for 3FOH, 93.0 Å for 6FOH, and 59.4 Å for 9FOH; the largest CLs of the films in both (010) and (020) peaks endow gNR-6FOH the highest electron mobility. ,, In addition, the lower paracrystalline disorder of π–π stacking for FA cast films (Figure S16d) also suggests the further structural ordering, which leads to a reduction of the number of structural trapping sites for the electron carriers and indicates a strong correlation with charge transport properties. , It is worth noting that the combination of edge orientation predominance, closer molecular stacking, and enhanced crystallinity always leads to a more effective electronic transport; i.e., gNR-6FOH possesses the highest 1.78 × 10 –2 cm 2 V –1 s –1 compared to 1.25 × 10 –2 cm 2 V –1 s –1 for gNR-CF , owing to its highest edge-on orientation ratio, closest distance and maximum coherence length, and lowest paracrystalline disorder for (020) π–π stacking .…”

“…Therefore, the predominance of edge-on orientation and tighter molecular packing for FA cast films are conducive to the effective charge transport in the parallel direction of the device architecture. 57,58 To gain insight into the crystallinity difference of gNR in thin films, coherence lengths (CLs) and paracrystalline disorder (g) were calculated from the width of the π−π stacking diffraction peaks (CL = 2πK/FWHM, K = 0.9, = g q FWHM 2 0…”

Crystallization-Driven Solution-State Assembly of Conjugated Block Copolymers in Materials Science

“…Lee and co-workers developed a facile strategy for preparing highly crystalline P3HT nanowires using a wide range of solvent mixtures, where the crystal growth rate was controlled by varying the solvent mixing rate (Figure 3c). 120 Chloroform, a good solvent for P3HT based on the HSP, was combined with orthogonal solvents (dichloromethane, hexane, acetonitrile, and methanol), and the solvent mixing rate, as well as the binary solvent selectivity, affected the solution-phase crystallinity of well-defined P3HT nanowires and the molecular orientation of the thin films. Notably, highly crystalline P3HT nanowires were obtained even using poor solvents, such as acetonitrile and methanol, by diffusing the orthogonal solvent slowly into the good solvent to slow down the crystallization rate.…”

“…Even at low concentrations, strong intermolecular interactions between polymers can lead to the rapid formation of aggregates in solution. The degree of polymer aggregation in a solution can be regulated by adjusting various parameters such as relative polymer–solvent interactions (solubility parameter and solvent quality), , dissolution temperature, polymer concentration, ultrasonication, ,, and ultraviolet (UV) irradiation. , …”

“…They found that the assembly of the poly­(3-butylthiophene)- block -poly­(3-hexylthiophene) (P3BHT- b -P3HT) leads to the formation of nanofibrils and nanorings as a function of the good/poor solvent (chloroform/anisole) ratio. Lee and co-workers developed a facile strategy for preparing highly crystalline P3HT nanowires using a wide range of solvent mixtures, where the crystal growth rate was controlled by varying the solvent mixing rate (Figure c) . Chloroform, a good solvent for P3HT based on the HSP, was combined with orthogonal solvents (dichloromethane, hexane, acetonitrile, and methanol), and the solvent mixing rate, as well as the binary solvent selectivity, affected the solution-phase crystallinity of well-defined P3HT nanowires and the molecular orientation of the thin films.…”