摘要
Inhibiting the ions migration and even irreversible reactions have been regarded as one of the most important factors for fabricating efficient and stable perovskite solar cells(PSCs).Here,we employed the diamine cobalt(II)porphyrin[Co(II)P]to treat a perovskite film to construct in situ Co(II)P-based coordination polymer on the perovskite film.The crystal structure of the polymer indicated a central cobalt(Co)ion in one Co(II)P coordinated with two amine units from a different neighboring Co(II)P to form an overall three-dimensional(3D)structure.Such a 3D network covered on the perovskite surface could prevent the migration of ions from the perovskite.Furthermore,the limited amount of diatomic iodine(I2)released in the perovskite due to iodide oxidation defects could be reduced to I–by the Co(II)ion in the polymer,and thus,achieve regeneration.Finally,the Co(Ⅱ/Ⅲ)ion pair formed in the polymer facilitated the charge transfer and boosted to the best efficiency up to 21.3%.Remarkably improved cell stability under moisture,heating,or light was also achieved.The control PSCs with Zn-based 3D polymer and Co-based 1D polymer exhibited the poor cell efficiencies and stabilities than those of the 3D Co porphyrin-based PSC to verify the effect of 3D Co porphyrin-based polymer in stabilizing the perovskite film.This work provides a new encapsulation and regeneration strategy via in situ construction of a Co(Ⅱ)porphyrin-based coordination polymer on perovskite film for efficient and stable PSCs.
基金
The authors acknowledge the National Natural Science Foundation of China(21801104 and 21871121)
Young Elite Scientists Sponsorship Program by CAST(2018QNRC001)
Fundamental Research Funds for the Central Universities(lzujbky-2019-sp01)
Special Fund Project of Guiding Scientific and Technological Innovation Development of Gansu Province(2019ZX-04).
