02130nas a2200253   4500008004100000245010800041210006900149260000800218300001400226490000600240520124600246653001901492653002501511653002601536653002301562653002301585653002701608100002301635700002201658700002601680700002101706700003001727856011901757       2022                        eng d00aInstabilities as the origin of large-area self-assembled and aligned organic semiconductor nanocrystals0 aInstabilities as the origin of largearea selfassembled and align  cAPR  a1815-18220 v43 a<p>
	Aligned nanocrystals of organic semiconductors (OSCs) are highly desirable for electronic devices and biomedical and photonic applications. Solution-based wet processing routes have the potential to produce aligned nanocrystals over large areas in small time frames. Herein, we demonstrate that by optimizing the hydrodynamic evaporative processes, controlled long-range crystalline assemblies of OSCs can be achieved (longest nanocrystal similar to 3 mm) purely through physical processes: namely, from fingering instabilities. Self-assembly is achieved here without strong noncovalent interactions such as hydrogen-bonding interactions. Experimentally our approach involves just placing a drop of a solution on an inclined substrate. Nanocrystals with widths of 300-800 nm and lengths of millimeters (length/width aspect ratios &gt;10(5)) are formed in less than 2-8 s. A hydrazine chemiresistive sensor based on the aligned crystalline patterns show unprecedented responsivity (similar to 10(-6)), 2 orders greater than those of stick-slip patterns. Finally, experimental parameters that need optimization to achieve nanocrystal patterns are investigated in detail and pointers to fabricate such OSC nanocrystals are provided.</p>
10aaligned fibers10adiketopyrrolopyrrole10afingering instability10ananocrystal arrays10anaphthalenediimide10aorganic semiconductors1 aVenugopalan, Vijay1 aJain, Bhanprakash1 aMahale, Rajashree, Y.1 aSubramani, Kumar1 aKrishnamoorthy, Kothandam  uhttp://library.ncl.res.in/content/instabilities-origin-large-area-self-assembled-and-aligned-organic-semiconductor02973nas a2200253   4500008004100000022001400041245015100055210006900206260000800275300001400283490000600297520205900303653001902362653002502381653001302406653001902419653002102438100002402459700002902483700002002512700002602532700003002558856013102588       2025                        eng d  a2637-610500aLong cycling stability imparted to li-ion batteries by conjugated polymers with low dihedral angles and high electron density on functional groups0 aLong cycling stability imparted to liion batteries by conjugated  cJUN  a7719-77280 v73 a<p>
	In conjugated polymers, dihedral angles at bonds connecting their monomers impact the polymers' properties such as the packing of the polymer chains, bandgap, and conductivity. These properties are expected to impact the performance of rechargeable Li-ion batteries because the Li-ion transport and conductivity of the polymers are two important parameters. To understand this, we designed and synthesized two polymers with two different dihedral angles. The polymer, Poly(EDOT-DPP), comprising diketopyrrolopyrrole (DPP) and ethylenedioxythiophene (EDOT) as monomers, showed a low dihedral angle of 2 degrees. On the other hand, the polymer, Poly(EDOT-i-Ind), comprising EDOT and i-Indigo (i-Ind) showed a dihedral angle of 17 degrees. Density functional theory (DFT) studies showed that the electron density at the carbonyl moiety of EDOT-DPP is higher than that of EDOT-i-Ind. This resulted in a higher Li+ binding energy of -3.665 eV for EDOT-DPP and a lower Li+ binding energy of -3.464 eV for EDOT-i-Ind. Battery electrodes were fabricated using either Poly(EDOT-DPP) or Poly(EDOT-i-Ind) with multiwalled carbon nanotubes as conducting fillers in the absence of any binders. The Li+ ion diffusion coefficient ( D Li + ) measured for the as prepared batteries based on Poly(EDOT-DPP) was found to be 3.9 x 10-19 cm2/s, which is slightly higher than that found for Poly(EDOT-i-Ind). However, after 2000 cycles, the D Li + increased by about two orders of magnitude for both polymers. Due to the low dihedral angle in the case of Poly(EDOT-DPP), the D Li + was found to be 21% higher than that of Poly(EDOT-i-Ind). The higher binding of Li+ ions with Poly(EDOT-DPP) and Li+ ion diffusion improved the specific capacity and cycling performance of batteries fabricated with this polymer. At a current density of 0.2 A/g, Poly(EDOT-DPP) showed a 39% higher specific capacity than the Poly(EDOT-i-Ind) polymer after 2000 cycles. The batteries also showed stable performance over 2000 cycles with an insignificant decrease in specific capacity.</p>
10adihedral angle10adiketopyrrolopyrrole10ai-indigo10aLi-ion battery10aLi-ion transport1 aKargude, Radhakisan1 aSrinivasalu, Hari, Haran1 aDevasia, George1 aKrishnamurty, Sailaja1 aKrishnamoorthy, Kothandam  uhttp://library.ncl.res.in/content/long-cycling-stability-imparted-li-ion-batteries-conjugated-polymers-low-dihedral-angles-and