The development of cost-effective,environmentally sustainable narrowband near-infrared(NIR)organic light-emitting diodes(OLEDs)remains challenging due to low intrinsic quantum yields of NIR emitters,as constrained by ...The development of cost-effective,environmentally sustainable narrowband near-infrared(NIR)organic light-emitting diodes(OLEDs)remains challenging due to low intrinsic quantum yields of NIR emitters,as constrained by the energy gap law and inefficient triplet exciton utilization.In this study,we present a conformation-locking strategy combined with donor engineering to enhance NIR emitters based on a boron-dipyrromethene(BODIPY)scaffold for high-performance solution-processed OLEDs.Two NIR emitters,Ph-BDP-Cz and Ph-BDP-PY,were synthesized by introducing a donor at the α-position of the BODIPY core via a vinyl bridge.This design increases molecular rigidity by promoting HF interactions between vinyl hydrogens and the BF2 group,suppressing twisting and scissoring motions,which results in narrow emission and high photoluminescence quantum yields.Donor engineering also enables fine-tuning of emission wavelengths without broadening the full-width at half-maximum(FWHM),maintaining a narrow emission profile.Using these BODIPY emitters in thermally activated delayed fluorescence(TADF)-sensitized hyperfluorescent OLEDs,we achieved a maximum external quantum efficiency(EQE)of 6.9%with an emission peak at 702 nm and a narrow FWHM of<45 nm.To our knowledge,this represents one of the highest efficiencies among TADF sensitized solution-processed NIR OLEDs,offering a promising path toward the development of sustainable and high-performance NIR optoelectronic devices.展开更多
Pure near-infrared(NIR)phosphorescent materials with emission peak larger than 700 nm are of great significance for the development of optoelectronics and biomedicine.We have designed and synthesized two new B-embedde...Pure near-infrared(NIR)phosphorescent materials with emission peak larger than 700 nm are of great significance for the development of optoelectronics and biomedicine.We have designed and synthesized two new B-embedded pure near-infrared(NIR)-emitting iridium complexes(Ir(Bpiq)2acac and Ir(Bpiq)2dpm)with peaks greater than 720 nm.More importantly,they exhibit very narrow phosphorescent emission with full width at half maximum(FWHM)of only about 50 nm(0.12 e V),resulting in a high NIR content(>90%)in their spectrum.In view of better optical property and solubility,the complex Ir(Bpiq)_(2)dpm was used as the emitting layer of a solution-processed OLED device,and achieved good maximum external quantum efficiency(EQE)(2.8%)peaking at 728 nm.This research provides an important strategy for the design of narrowband NIR-emitting phosphorescent iridium complexes and their optoelectronic applications.展开更多
基金financially supported by Natural Science Foundation of Guangdong Province(No.2022B1515020041)National Natural Science Foundation of China(Nos.22350410384,52273179,52303228,U23A20594)+1 种基金Guangzhou Basic and Applied Basic Research(No.2023A04J1374)the Instrumental Analysis Center of Guangdong University of Technology for their support。
文摘The development of cost-effective,environmentally sustainable narrowband near-infrared(NIR)organic light-emitting diodes(OLEDs)remains challenging due to low intrinsic quantum yields of NIR emitters,as constrained by the energy gap law and inefficient triplet exciton utilization.In this study,we present a conformation-locking strategy combined with donor engineering to enhance NIR emitters based on a boron-dipyrromethene(BODIPY)scaffold for high-performance solution-processed OLEDs.Two NIR emitters,Ph-BDP-Cz and Ph-BDP-PY,were synthesized by introducing a donor at the α-position of the BODIPY core via a vinyl bridge.This design increases molecular rigidity by promoting HF interactions between vinyl hydrogens and the BF2 group,suppressing twisting and scissoring motions,which results in narrow emission and high photoluminescence quantum yields.Donor engineering also enables fine-tuning of emission wavelengths without broadening the full-width at half-maximum(FWHM),maintaining a narrow emission profile.Using these BODIPY emitters in thermally activated delayed fluorescence(TADF)-sensitized hyperfluorescent OLEDs,we achieved a maximum external quantum efficiency(EQE)of 6.9%with an emission peak at 702 nm and a narrow FWHM of<45 nm.To our knowledge,this represents one of the highest efficiencies among TADF sensitized solution-processed NIR OLEDs,offering a promising path toward the development of sustainable and high-performance NIR optoelectronic devices.
基金support from the National Natural Science Foundation of China(Nos.22171109,52373195 and 22001097)Natural Science Foundation of Jiangsu Province of China(No.BK20201003)+1 种基金the Postdoctoral Research Foundation of China(No.2021M701657)the Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices,Ministry of Education,Jianghan University(No.JDGD-202301)。
文摘Pure near-infrared(NIR)phosphorescent materials with emission peak larger than 700 nm are of great significance for the development of optoelectronics and biomedicine.We have designed and synthesized two new B-embedded pure near-infrared(NIR)-emitting iridium complexes(Ir(Bpiq)2acac and Ir(Bpiq)2dpm)with peaks greater than 720 nm.More importantly,they exhibit very narrow phosphorescent emission with full width at half maximum(FWHM)of only about 50 nm(0.12 e V),resulting in a high NIR content(>90%)in their spectrum.In view of better optical property and solubility,the complex Ir(Bpiq)_(2)dpm was used as the emitting layer of a solution-processed OLED device,and achieved good maximum external quantum efficiency(EQE)(2.8%)peaking at 728 nm.This research provides an important strategy for the design of narrowband NIR-emitting phosphorescent iridium complexes and their optoelectronic applications.
