Light-emitting electrochemical cells(LECs)can be fabricated with cost-efficient printing and coating methods,but a current drawback is that the LEC emitter is commonly either a rare-metal complex or an expensive-to-sy...Light-emitting electrochemical cells(LECs)can be fabricated with cost-efficient printing and coating methods,but a current drawback is that the LEC emitter is commonly either a rare-metal complex or an expensive-to-synthesize conjugated polymer.Here,we address this issue through the pioneering employment of metal-free and facile-to-synthesize carbon nanodots(CNDs)as the emitter in functional LEC devices.Circular-shaped(average diameter=4.4 nm)and hydrophilic CNDs,which exhibit narrow cyan photoluminescence(peak=485 nm,full width at half maximum=30 nm)with a high quantum yield of 77%in dilute ethanol solution,were synthesized with a catalyst-free,one-step solvothermal process using low-cost and benign phloroglucinol as the sole starting material.The propensity of the planar CNDs to form emission-quenching aggregates in the solid state was inhibited by the inclusion of a compatible 2,7-bis(diphenylphosphoryl)-9,9’-spirobifluorene host compound,and we demonstrate that such pristine host-guest CND-LECs turn on to a peak luminance of 118 cd·m^(−2)within 5 s during constant current-density driving at 77 mA·cm^(−2).展开更多
基金support from J.C.Kempes Minnes Stipendiefond(No.SMK-1849.1)the Swedish Energy Agency(Nos.45419-1,46523-1,and 50779-1)+2 种基金the Swedish Research Council(Nos.2017-04380,2017-04862,2018-03937,and 2019-02345)the Swedish Foundation for Strategic Research,Stiftelsen Olle Engkvist Byggmästare(Nos.186-0637 and 193-0578)Bertil&Britt Svenssons stiftelse för belysningsteknik,the Swedish Foundation for International Cooperation in Research and Higher Education via an Initiation Grant for Internationalization(No.2019-8553)。
文摘Light-emitting electrochemical cells(LECs)can be fabricated with cost-efficient printing and coating methods,but a current drawback is that the LEC emitter is commonly either a rare-metal complex or an expensive-to-synthesize conjugated polymer.Here,we address this issue through the pioneering employment of metal-free and facile-to-synthesize carbon nanodots(CNDs)as the emitter in functional LEC devices.Circular-shaped(average diameter=4.4 nm)and hydrophilic CNDs,which exhibit narrow cyan photoluminescence(peak=485 nm,full width at half maximum=30 nm)with a high quantum yield of 77%in dilute ethanol solution,were synthesized with a catalyst-free,one-step solvothermal process using low-cost and benign phloroglucinol as the sole starting material.The propensity of the planar CNDs to form emission-quenching aggregates in the solid state was inhibited by the inclusion of a compatible 2,7-bis(diphenylphosphoryl)-9,9’-spirobifluorene host compound,and we demonstrate that such pristine host-guest CND-LECs turn on to a peak luminance of 118 cd·m^(−2)within 5 s during constant current-density driving at 77 mA·cm^(−2).
