Low-cost and stable SFX-based semiconductor materials in organic optoelectronics

In the progress of realizing the commercialization of organic optoelectronic materials,the four basic coherent factors are stability,cost,performance,and processability,all which determine the results of device applications.Spiro[fluorene-9,9′-xanthene](SFX)has been becoming the robust building-block that fulfilling the practical requirements due to its key features of non-planarity,one-pot facile availability,well-defined quality assurance as well as performance behaviors.In this review,we introduce the SFX and its analogues,including synthesis,molecular design,device performance,and structure-property relationship,in the applications of organic light-emitting diodes(OLEDs),organic photovoltaics,perovskite solar cells(PSCs)and others.Furthermore,emitters or hosts for OLED and hole transport materials for PSCs are highlighted at the level of molecular configuration and film morphology.Tracing the thread from intrinsic photoelectric properties,molecular packing to optoelectronic application,the advantage of stability and low-cost of SFX-based materials are illuminated,and an outlook is given providing orientation for bring SFX into the fields of catalysis and energy chemistry in view of its binary conjugation and three-dimensional configuration.

A crosslinked polymer as dopant-free hole-transport material for efficient n-i-p type perovskite solar cells

A new crosslinked polymer,called P65,with appropriate photo-electrochemical,opto-electronic,and thermal properties,has been designed and synthesized as an efficient,dopant-free,hole-transport material(HTM)for n-i-p type planar perovskite solar cells(PSCs).P65 is obtained from a low-cost and easily synthesized spiro[fluorene-9,90-xanthene]-30,60-diol(SFX-OH)-based monomer X65 through a freeradical polymerization reaction.The combination of a three-dimensional(3 D)SFX core unit,holetransport methoxydiphenylamine group,and crosslinked polyvinyl network provides P65 with good solubility and excellent film-forming properties.By employing P65 as a dopant-free hole-transport layer in conventional n-i-p type PSCs,a power conversion efficiency(PCE)of up to 17.7%is achieved.To the best of our knowledge,this is the first time a 3 D,crosslinked,polymeric dopant-free HTM has been reported for use in conventional n-i-p type PSCs.This study provides a new strategy for the future development of a 3 D crosslinked polymeric dopant-free HTM with a simple synthetic route and low-cost for commercial,large-scale applications in future PSCs.