Study On The Ordered Heterojunction Materials Based On Slef-assembly Of The Block Copolymer—Synthesis Of Conductive Polymer And The Preparation Of The Heterojunction

In previous work, we have systematically investigated the phase behavior of thin films of polystyrene cylinder-forming polystyrene-poly(methyl methacrylate)(PS-b-PMMA) diblock copolymer. By using substrate modification method, the vertically oriented PS cylinders were obtained in the diblock copolymer thin films on the conducting glass (ITO). Subsequently, the TiO2sol was added to the PS nanopillar scaffold. After sintered, rang-ordered TiO2nanoporous film was obtained. The methods are detailed in the third chapter.In this paper, we used chain growth Kumada catalyst-transfer polycondensation to synthesize head-tail poly(3-hexylthiophene)(HT-P3HT). The influences of the amounts of catalyst Ni(dppp)Cl2and the additive LiCl on the molecular weight (Mn) and polydispersity (PDI) of the P3HT were investigated. The structure and molecular weight of P3HT was characterized by1H-NMR and GPC. The data of the1H-NMR indicated that the polymers exhibited high regularity and the data of GPC suggested that the P3HT obtained as LiCl used as an additives were of higher molecular weight and narrower polydispersity comparing with those obtained as LiCl was absent. The Mn and PDI of the P3HT were no longer in linear relationship with the molar ratio of the monomer to the catalyst, and the regularity was little down.The physical properties of HT-P3HT were investigated by XRD (X-ray diffraction), AFM (Atom Force Microscopy), Ultraviolet-visible Spectroscopy. From the profile of XRD, it is found that the P3HT films showed considerable crystalline structure. The formation of π overlap along the backbone is confirmed and the maximum absorption (λmax) values for HT-P3HT in solution and film are459nm and559nm based on ultraviolet-visible spectroscopy, respectively. This red shift was attributed to the increase of the extent of conjugation in film. The morphology of P3HT film was characterized by AFM, the images of AFM show that a less ordered morphology with short "grain" is observed. After thermal annealing treatment, the size of the "grain" increases, the roughness of thin film becomes larger.The conductive polymer poly(3-hexylthiophene)(HT-P3HT) were filled into the prepared TiO2ordered inorganic nanoporous film and the ordered heterojunction structure polymer solar cell (ITO/Ti02/P3HT/Au) was made. We obtained the open circuit voltage of0.34V, short-circuit current of0.27mA, fill factor of0.43and power conversion efficiency of0.04in AM1.5G light, at100mW/cm-2illumination.