Preparation And Structure Research Of Oriented Poly(3-hexylthiophene) Thin Films

Because of its remarkable optoelectronic properties,poly(3-hexylthiophene)(P3HT)has become one of the most promising semi-conductive polymer and has been widely applied in various devices,such as solar cells and field-effect transistors.The morphology and structure of P3HT films have a significant effect on charge transport.Therefore,precise regulation of film morphology means a lot to optimize device performance.We use 1,3,5-trichlorobenzene(TCB)as a crystallizable small molecule solvent to prepare highly oriented P3HT fims by surface-inducing.The work was divided into the following two parts:1.Surface-induction to prepare oriented P3HT spherulite-like filmHighly oriented P3HT spherulite-like films can be prepared by spin-coating from a mixture of 1,3,5-trichlorobenzene(TCB)and chloroform.During the process of spin-coating,TCB starts to solidify and nucleate to initiate the growth of spherulites on substrate.Then epitaxial crystallization of P3HT on TCB spherulites leads to a similar structure of P3HT film.There is a "fish-eye" region in the center of every spherulite-like structure,which give the possibility of P3HT film to anisotropic.Highly oriented PE film adopted as the substrate for epitaxial crystallization of P3HT can induce the uniform arrangement of P3HT spherulite-like structure and finally obtained a oriented P3HT spherulite-like film.Besides,the addition of TCB leads to the increase of face-on lamellae in P3HT films.2.Surface-induction to prepare oriented P3HT fibrous filmHighly oriented P3HT fibrous films can be prepared by dip-coating from a mixture of 1,3,5-trichlorobenzene(TCB)and chloroform.During the process of dip-coating,TCB starts to solidify and form nucleus to initiate growth the pulling direction.Then epitaxial crystallization of P3HT on TCB fibers leads oriented P3HT fibrous film with all long fiber aligned with the pulling direction.The addition of TCB leads to the increase of face-on lamellae in P3HT films.Besides,we have explored the factors affecting the degree of orientation of P3HT fibrous film,and conclude that with the faster speed of the carrier solvent volatilization,the faster pulling speed,and the greater concentration of TCB,the higher degree of orientation of the prepared P3HT film will realize.