摘要
The effects of replacement on the optical properties of diketopyrrolopyrrole(DPP)-based polymers were discussed through replacing the thieno[3,2-b]thiophene units by thiophene units.It is easy to see that the role of replacement would lead to blue shift of steady-state absorption spectrum when thieno[3,2-b]thiophene units is replaced by thiophene units.Meanwhile,the transient absorption data indicate that the role of replacement would not change the relaxation mechanism of polymer,but is able to adjust the photo-excitation relaxation rate of polymer.Their intensity-dependent dynamic curves show that the exciton-exciton annihilation(EEA)would participate in the relaxation process when the polymer is in the aggregation.Through comparing the EEA data between the polymers,it is found that the role of replacement would change the spatial distribution of exciton.
基金
the National Natural Science Foundation of China(Nos.21573094,51502109,11774122,11574112,11474131 )
the National Found for Fostering Talents of Basic Science of China(No.J1103202)
the Science and Technology Projects in the 13th Five-year Plan of the Education Department of Jilin Province,China(No.2016-402 ).