The invention discloses a
polymer material containing a large-volume branching alkoxy
side chain, as well as a preparation method and application of the
polymer material, belonging to the technical field of new energies. The
polymer material is designed by adopting a PBDT-DTBTff (4,8-bis(alkyloxy) benzo-[1,2-b:4,5-b']dithiophene / 5,6-Difluoro-4,7-bis(5-bromo-4-(
alkyl)-2-thienyl)-2,1,3-benzothiadiazole) main
chain structure with high photoelectric property; through introducing a large-volume branching alkoxy
side chain structure in a BDT unit and introducing a large-volume alkoxy
side chain structure in a DTBTff structure unit, the
solubility of a polymer is improved while high photoelectric property of a conjugated polymer is maintained, and thus the polymer is more uniformly mixed with a
fullerene derivative PCBM (Phenyl Cn
Butyric Acid Methyl Ester). In a solution, a
solar cell device
active layer film formed by deposition has an ideal phase structure, higher device
transformation efficiency (more than 7 percent) can be obtained under the condition with no need of any post-treatment, and the problem of difficulty in post-treatment during large-scale device civilianized production of existing polymer solar cells can be solved.