Preparation And Properties Of Anisotropic P3HT Films And P3HT/PCBM Blend Films

Conductive polymer films are widely used in many fields,such as organic electronic semiconductor materials,sensor materials,photoelectric conversion materials and so on.The performance of the conductive polymer film is closely related to its structure at the surface and interface.Therefore,regulating the surface and interface structure of the conductive polymer is an important method to optimize its performance.In this paper,the structure of P3HT thin film and P3HT/PCBM blends was controlled by selecting different kinds of substrates and solvents.The work was divided into the following two parts:1.The highly oriented PE substrates induces the anisotropy of the P3HT filmThe P3HT films with different characteristics were prepared by changing the evaporation rates of chloroform solvent in P3HT solution on quartz and oriented PE substrates.The structure,morphology and electrical properties of P3HT films were characterized by polarizing microscope(POM),atomic force microscopy(AFM)and semiconductor parameter tester.The P3HT films prepared by slow evaporation rates of chloroform solvent on PE substrates(P3HT/PE-SE)due to the epipolar crystallization of PE,a large number of c-axis parallel to the PE films was formed.And the conductivity of P3HT is anisotropy.The P3HT/PE-SE film exhibits the highest conductivity in the direction parallel to the stretching of PE substrates(10 ± 0.5 Scm-1),while the conductivity of the P3HT films prepared by slow evaporation rates of chloroform solvent on PE substrates(P3HT/PE-SE)is almost the same as that measured on the quartz substrates(1.5 ± 0.2 Scm-1).2.Effect of different substrates on the structure of P3HT/PCBM blend filmsThe P3HT/PCBM blend films were prepared on quartz,PSS:PEDOT and highly oriented PE substrates.The crystalline morphology of P3HT/PCBM blends on PSS:PEDOT substrates is similar to that of quartz substrates,while on PSS:PEDOT substrates the formation of P3HT face-on structure is promoted.On the PE substrates,the orientation of P3HT in blends was induced by PE substrates.The formation of face-on structure was promoted remarkably,which provided the basis for regulating the vertical phase separation of donor-acceptor materials of solar cell active layer.