超小荧光分子实现单层白光电致发光二极管OA

White organic light-emitting diodes(WOLEDs)are promising candidates for solid-state lighting and full-color display due to their advantages such as energy conservation,thinness,lightness and flexible display.Tradi-tional WOLEDs mostly adopt multi-layer architectures that stack primary-color emitters(red,green,and blue)to achieve white emission.However,these devices suffer from complicated fabrication and high manufacturing costs.Therefore,solution-processed single emissive layer WOLEDs have attracted extensive research attention.In this study,an ultra-small organic fluorescent molecule(4,7-bis(thiophen-2-yl)benzo[c][1,2,5]thiadiazole,TBT)composed solely of a thiadiazole acceptor and a thiophene donor was designed and synthesized,which exhibits a broad yellow-orange emission ranging from 450 nm to 650 nm,with a peak at 560 nm.By blending TBT with poly(N-vinylcarbazole)(PVK)and 1,3-bis(5-(4-tert-butylphenyl)-1,3,4-oxadiazol-2-yl)benzene(OXD-7)in a single emissive layer,we obtain cool-white,pure-white,and warm-white electroluminescence covering 400-650 nm.The optimized device delivers a maximum external quantum efficiency of 2.3%and a peak luminance of 4 000 cd/m².Owing to its low-cost and simple synthesis,solution processability,and high efficiency,this ultra-small fluorescent molecule provides a feasible approach for low-cost lighting and display applications.