Ultralong excimer phosphorescence by the self-assembly and confinement of terpyridine derivatives in polymeric matrices

Ultralong organic room temperature phosphorescence(RTP)is attracting increas-ing attention due to its fascinating optical phenomena and wide applications.Among various RTP,excimer phosphorescence is of fundamental significance,but it remains a considerable challenge to achieveflexible,multicolor and large-area excimer RTP materials,which should greatly advance the understanding and devel-opment of organic light-emitting devices.Herein,we present ultralong excimer RTPfilms by the self-assembly and confinement of terpyridine(Tpy)derivatives in polymeric matrices.Strikingly,the self-assembly of Tpy derivatives induces the formation of excimer complexes,thus immensely minimizing singlet-triplet split-ting energy(ΔEST)to promote the intersystem crossing process.Furthermore,the confinement by multiple hydrogen bonding interactions as well as the compact aggregation of phosphors jointly suppresses the nonradiative transitions,leading to long-lived excimer RTP(τ543.9 ms,19,000-fold improvements over the pow-=der).On account of the outstanding afterglow performance and color-tunability of RTP materials,flexible and large-areafilms were fabricated for intelligent display,anticounterfeiting,and time-resolved information encryption.