Light-emitting electrochemical cells(LECs),featuring simple device structures and low-cost solution processability,have garnered considerable attention for display and lighting applications,but they face challenges in...Light-emitting electrochemical cells(LECs),featuring simple device structures and low-cost solution processability,have garnered considerable attention for display and lighting applications,but they face challenges in achieving high efficiency and high color purity.Herein,we report two ionic multi-resonance(MR)emitters with narrowband blue emission for high-color-purity LECs,by covalently bonding an imidazolium functional group into a boron(B)/nitrogen(N)-doped polycyclic skeleton.This design not only maintains narrowband emission and high photoluminescence quantum yield(PLQY)of the MR skeleton,but also harnesses the functions of two kinds of N atoms(pyrrolic and pyridinic N atoms)within the imidazolium unit.On the one hand,the 1-position pyrrolic N atom with electron-rich character forms a para-B-π-N linkage with the MR skeleton,elevating the excited-state energy levels and blue-shifting the emission band.On the other hand,the 3-position pyridinic N atom provides a quaternization site to form intrinsically ionic emitters compatible with ionic hosts.Such emitters exhibit blue emission with narrow full-widths at half-maximum of 26–27 nm,and high PLQYs of 95%–97%in solid-state films.LECs based on these emitters exhibit narrowband blue emission with CIE coordinates of(0.12,0.26)and a maximum external quantum efficiency of 4.6%,representing the first narrowband blue LECs based on intrinsically ionic MR emitters.展开更多
基金supported by the National Natural Science Foundation of China(22405067,22475058)the Hainan Province Science and Technology Special Fund(ZDYF2025SHFZ026)+3 种基金the Innovation Fund for Scientific and Technological Personnel of Hainan Province(KJRC2023D35,KJRC2023C09)the National Natural Science Foundation of Hainan Province(224QN183,524MS031)the Open Project of State Key Laboratory of Supramolecular Structure and Materials(sklssm202510)the Startup Scientific Research Foundation from Hainan University(KYQD(ZR)23096,KYQD(ZR)22174)。
文摘Light-emitting electrochemical cells(LECs),featuring simple device structures and low-cost solution processability,have garnered considerable attention for display and lighting applications,but they face challenges in achieving high efficiency and high color purity.Herein,we report two ionic multi-resonance(MR)emitters with narrowband blue emission for high-color-purity LECs,by covalently bonding an imidazolium functional group into a boron(B)/nitrogen(N)-doped polycyclic skeleton.This design not only maintains narrowband emission and high photoluminescence quantum yield(PLQY)of the MR skeleton,but also harnesses the functions of two kinds of N atoms(pyrrolic and pyridinic N atoms)within the imidazolium unit.On the one hand,the 1-position pyrrolic N atom with electron-rich character forms a para-B-π-N linkage with the MR skeleton,elevating the excited-state energy levels and blue-shifting the emission band.On the other hand,the 3-position pyridinic N atom provides a quaternization site to form intrinsically ionic emitters compatible with ionic hosts.Such emitters exhibit blue emission with narrow full-widths at half-maximum of 26–27 nm,and high PLQYs of 95%–97%in solid-state films.LECs based on these emitters exhibit narrowband blue emission with CIE coordinates of(0.12,0.26)and a maximum external quantum efficiency of 4.6%,representing the first narrowband blue LECs based on intrinsically ionic MR emitters.
