Perovskite solar cells(PSCs)have seen remarkable progress in recent years,largely attributed to various additives that enhance both efficiency and stability.Among these,fluorine-containing additives have garnered significant interest because of their unique hydrophobic properties,effective defect passivation,and regulation capability on the crystallization process.However,a targeted structural approach to design such additives is necessary to further enhance the performance of PSCs.Here,fluoroalkyl ethylene with different fluoroalkyl chain lengths(CH_(2)CH(CF_(2))nCF_(3),n=3,5,and 7)as liquid additives is used to investigate influences of fluoroalkyl chain lengths on crystallization regulation and defect passivation.The findings indicate that optimizing the quantity of F groups plays a crucial role in regulating the electron cloud distribution within the additive molecules.This optimization fosters strong hydrogen bonds and coordination effects with FA+and uncoordinated Pb^(2+),ultimately enhancing crystal quality and device performance.Notably,1H,1H,2H-perfluoro-1-hexene(PF_(3))with the optimal number of F presents the most effective modulation effect.A PSC utilizing PF_(3)achieves an efficiency of 24.05%,and exhibits exceptional stability against humidity and thermal fluctuations.This work sheds light on the importance of tailored structure designs in additives for achieving high-performance PSCs.
This review profiles twelve fluorine-containing drugs approved by the US Food and Drug Administration(FDA) for the clinic in 2023.These small molecule drugs represent such therapeutic areas as cancer,neuromuscular disorder,immunodeficiency,virology,and infectious diseases.Medicinal chemistry discovery,biological activity,and synthetic routes have been discussed for each drug.Also,new trends in structural positioning,functionality,and degree of fluorination are discussed.Besides fluorination,the importance of amino acid residues and chirality in the design of new pharmaceuticals is highlighted.
Qian WangYeping BianGagan DhawanWei ZhangAlexander E.SorochinskyAta MakaremVadim A.SoloshonokJianlin Han