| In recent years, polythiophene have attracted considerable attention because of their great potential in photovoltaic cells, light emitting diodes (LED) and field effect transistors (FET). In order to realize the material application, their photoelectric properties need to be improved.This properties are related to the chemical structure of the material. Besides, it is affected the morphology on the substrate after the polymer assembly.Currently, the study of the assembly morphogenesis focused on with a branched-chain polythiophene, temperature, single solvents, and different substrate. However, there are little studies focused on the non-chiral polymer without side chains, the formation mechanism and the assembly structure of the mixed solvent. This paper obtain the formation mechanism of polythiophene film under the different solvents, the helical fibers were prepared with achiral molecules. It also studt the condition of polythiophene fiber formation in mixed solvent. The main contents of the study in this manuscript are as follows:1. By controlling the concentration ofα,ω-Dihexylsexithiophene chloroform solution, we observe the polythiophene on mica though Atomic Force Microscopy. Compared with the morphology of a, co-Dihexylsexithiophene dissolve in tetrahydrofuran, toluene and benzene than self-assembly on mica, we obtain the mechanism of the a, co-Dihexylsexithiophene self-assembly on mica from different solution and draw the model. We hope that it will increase the recognition of the monolayer dynamics simulation and theoretical model of films'formation. Besides, it expects the polythiothene layers which we obtained have great potential applications in PV systems.2. We successfully prepared fibers with helical structure by non-chiral molecule, a-Sexithiophene, in chloroform, tetrahydrofuran, benzene solution. Meanwhile, we study the effect of 2,2'2':5',2"-Terthiophene and 3,3"'-Didodecyl-2, 2':,2":5",2'"- quaterthiophene nanofibers assembled in different polarity mixture solvent, and obtain the best conditions for fiber formation. It provides the reference in development of organic semiconductor by controlling different solvent volume ratio to assemble fibers.3.The STM study ofα,ω-Dihexylsexithiophene adsorb on Au (111) surface. Result display that flat-lying adsorption introduced molecular chirality:right- and left-handed molecules separate into domains of two different orientations which are mirror symmetric with respect to the<121>direction of the Au (111) substrate. Molecule was stretched in the two domains with end-to-tail and arranged parallel to each other. The molecular axis deviated from the main axis of the Au(111) substrate by 5.4±0.6°and their hexyl chains deviated from [110] of the Au(111) substrate by 17.4±0.6°. These values correspond to 8 and 4√3 times of the Au lattice parameter (i.e.,8 x 0.289 and 4√3 x 0.289 nm), which indicates a (8 x 4√3)R30°structure with one molecule per unit cell. Accordingly, the surface concentration is measured to be 3.59x10-11mol cm-2. |
