Developing metal-free and long lifetime room-temperature phosphorescence(RTP)materials has received tremendous interest due to their numerous potential applications,of which stable triplet-excited state is the core ch...Developing metal-free and long lifetime room-temperature phosphorescence(RTP)materials has received tremendous interest due to their numerous potential applications,of which stable triplet-excited state is the core challenge.Here,boron carbon oxynitride(BCNO)dots,emitting stable blue fluorescence and green RTP,are reported for the first time.The obtained BCNO dots exhibit an unexpected ultralong RTP lifetime of 1.57 s,lasting over 8 s to naked eyes.The effective doping of carbon and oxygen elements in boron nitride(BN)actually provides a small energy gap between singlet and triplet states,facilitating the intersystem crossing(ISC)and populating of triplet excitons.The formation of compact cores via crystallization and effective inter-/intra-dot hydrogen bonds further stabilizes the excited triplet states and reduces quenching of RTP by oxygen at room temperature.Based on the water-soluble feature of BCNO dots,a novel advanced security ink is developed toward anti-counterfeiting tag and confidential information encryption.This study extends BCNO dots to rarely exploited phosphorescence fields and also provides a facile strategy to prepare ultralong lifetime metal-free RTP materials.展开更多
基金The authors are grateful to the National Natural Science Foundation of China(NSFC)(Nos.51872172 and 51972197)Natural Science Foundation of Shandong Province(Nos.ZR2018MEM010 and ZR2019MEM021)+1 种基金Major Research and Development Program for Public Welfare in Shandong(No.2018GGX102021)Young Scholars Program of Shandong University.
文摘Developing metal-free and long lifetime room-temperature phosphorescence(RTP)materials has received tremendous interest due to their numerous potential applications,of which stable triplet-excited state is the core challenge.Here,boron carbon oxynitride(BCNO)dots,emitting stable blue fluorescence and green RTP,are reported for the first time.The obtained BCNO dots exhibit an unexpected ultralong RTP lifetime of 1.57 s,lasting over 8 s to naked eyes.The effective doping of carbon and oxygen elements in boron nitride(BN)actually provides a small energy gap between singlet and triplet states,facilitating the intersystem crossing(ISC)and populating of triplet excitons.The formation of compact cores via crystallization and effective inter-/intra-dot hydrogen bonds further stabilizes the excited triplet states and reduces quenching of RTP by oxygen at room temperature.Based on the water-soluble feature of BCNO dots,a novel advanced security ink is developed toward anti-counterfeiting tag and confidential information encryption.This study extends BCNO dots to rarely exploited phosphorescence fields and also provides a facile strategy to prepare ultralong lifetime metal-free RTP materials.
