Perovskite solar cells(PSCs)have rapidly developed in the past few years,with a record efficiency exceeding 25%.However,the long-term stability of PSCs remains a challenge and limits their practical application.Many h...Perovskite solar cells(PSCs)have rapidly developed in the past few years,with a record efficiency exceeding 25%.However,the long-term stability of PSCs remains a challenge and limits their practical application.Many high-performance PSCs have an n-i-p device architecture employing 4-tert-butylpyridine(t-BP)and bis(trifluoromethane)sulfonimide lithium salt(Li-TFSI)as bi-dopants for the hole-transporting layer(HTL).However,the hygroscopicity of Li-TFSI and low boiling point of t-BP negatively impact the moisture stability of these PSC devices.Herein,we report the use of the fluorine-containing hydrophobic compound tris(pentafluorophenyl)phosphine(35FP)as a dopant for poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA).With better hydrophobicity and stability than undoped PTAA,a PSC device containing 35FP-doped PTAA demonstrated improved charge transport properties and reduced trap density,leading to a significant enhancement in performance.In addition,the long-term stability of a 35FP-doped PTAA PSC under air exposure without encapsulation was demonstrated,with 80%of the initial device efficiency maintained for 1,000 h.This work provides a new approach for the fabrication of efficient and stable PSCs to explore hydrophobic dopants as a substitute for hydrophilic Li-TFSI/t-BP.展开更多
基金This study was supported by the National Natural Science Foundation of China(Nos.61974054 and 61675088)the International Science&Technology Cooperation Program of Jilin(No.20190701023GH)+1 种基金the Scientific and Technological Developing Scheme of Jilin Province(Nos.20200401045GX)the Project of Science and Technology Development Plan of Jilin Province(No.20190302011G).
文摘Perovskite solar cells(PSCs)have rapidly developed in the past few years,with a record efficiency exceeding 25%.However,the long-term stability of PSCs remains a challenge and limits their practical application.Many high-performance PSCs have an n-i-p device architecture employing 4-tert-butylpyridine(t-BP)and bis(trifluoromethane)sulfonimide lithium salt(Li-TFSI)as bi-dopants for the hole-transporting layer(HTL).However,the hygroscopicity of Li-TFSI and low boiling point of t-BP negatively impact the moisture stability of these PSC devices.Herein,we report the use of the fluorine-containing hydrophobic compound tris(pentafluorophenyl)phosphine(35FP)as a dopant for poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA).With better hydrophobicity and stability than undoped PTAA,a PSC device containing 35FP-doped PTAA demonstrated improved charge transport properties and reduced trap density,leading to a significant enhancement in performance.In addition,the long-term stability of a 35FP-doped PTAA PSC under air exposure without encapsulation was demonstrated,with 80%of the initial device efficiency maintained for 1,000 h.This work provides a new approach for the fabrication of efficient and stable PSCs to explore hydrophobic dopants as a substitute for hydrophilic Li-TFSI/t-BP.
