A facile solution process for the fabrication of organic single crystal semiconductor devices which meets the demand for low-cost and large-area fabrication of high performance electronic devices is demonstrated. In this paper, we develop a bottom-up method which enables direct formation of organic semiconductor single crystals at selected locations with desired orientations. Here oriented growth of one-dimensional organic crystals is achieved by using self-assembly of organic molecules as the driving force to align these crystals in patterned regions. Based upon the self-organized organic single crystals, we fabricate organic field effect transistor arrays which exhibit an average field-effect mobility of 1.1 cm2V−1s−1. This method can be carried out under ambient atmosphere at room temperature, thus particularly promising for production of future plastic electronics.
A new C(3v)-symmetrical calix[6]azacryptand, that is, calix[6]tmpa (11), was synthesized by efficient [1+1] macrocyclization reactions. Remarkably, both linear and convergent synthetic strategies that were applied lead to equally good overall yields. Calix[6]tmpa behaves as a single proton sponge and appeared reluctant to undergo polyprotonation, unlike classical tris(2-pyridylmethyl)amine (tmpa) derivatives. It also acts as a good host for ammonium ions. Interestingly, it strongly binds a sodium ion and a neutral guest molecule, such as a urea, an amide, or an alcohol, in a cooperative way. A (1)H NMR study indicated that the ligand, as well as its complexes, adopt a major flattened cone conformation that is the opposite of that observed with the previously reported calix[6]cryptands. Characterization of the monoprotonated derivative 11H(+) by X-ray diffraction also revealed the presence of a 1,3-alternate conformation, which is the first example of its kind in the calix[6]arene family. This conformer is probably also present in solution as a minor species. The important covalent constraint induced by the polyaromatic tmpa cap on the calixarene skeleton, and conversely from the calix core onto the tmpa moiety, is the likely basis for the unique conformational and chemical properties of this host.
We report single crystal formation of organic semiconducting small molecules via solvent vapor annealing (SVA) on a polymer base film (PBF). The soluble PBF strongly assists the self-assembly of small molecules to form single crystals; this sharply contrasts typical SVA where the inorganic base film such as SiO 2 plays little or no role. We use a matrix of organic solvents and polymers to systematically investigate the re-crystallization of dioctylbenzothienobenzothiophene (C8-BTBT) by SVA on polymer surfaces. Crystallization by SVA clearly correlates with the miscibility of solvents and PBFs. The PBF dramatically increases the amount of condensed solvent on the surface. The additional solvent enhances the molecular mobility of small molecules to allow self-assembly in a distance over hundreds of microns, and stimulates crystal growth via Ostwald ripening. Based on this mechanism, the final crystal size of small molecules can be controlled to vary from tens of microns to millimetres simply by modifying the thickness of the base film. The approach was successfully applied to several semiconducting small molecules to form single crystals that exhibited field-effect response. Hence SVA on PBF is presented as a general and promising method for the direct fabrication of organic single crystals on polymer dielectrics.
A copper(I) halide-based compound with a formula of [Cu4I3(DABCO)2]I3 (DABCO = N,N'-dimethyl-1,4-diazabicyclo[2.2.2]octane) has been prepared by solvothermal reactions. This compound has been characterized by single-crystal X-ray diffraction, elemental analysis, IR, TG, XPS and powder X-ray diffractions. Structure analyses reveal that this compound is constructed by unprecedented cationic cluster [Cu8I6](2+) and organic ligand DABCO and the channels of this compound are occupied by I2 and I(-). The guest I2 and I(-) can move freely in and out of the host-framework. UV/vis spectra confirm that the I2 molecules in the channels can release into some organic solvents and IR spectra confirm the I(-) was exchanged by SCN(-). In addition, the luminescent properties of this compound in the solid state have also been investigated.
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