Performance improvement of polymer light-emitting diodes based on fluorene copolymer with cesium fluoride/aluminum cathode
CsF/Al阴极对提高芴基饱和红光器件性能的研究

Polymer light-emitting diodes with saturated red emission were fabricated using the copolymer,poly 2,7-(9,9-dioctyl)fluorene-co-5,5'-(4,7-diselenophenyl)-2,2'-yl-2,1,3-benzothiadiazole](PFO-SeBT).Special attention was paid to polymer/electrode interface modification.The highest electroluminescence external quantum efficiency of 1.79%,which was more than twice that of devices with low work function metal cathode Ba/Al,was achieved by incorporation of CsF/Al cathode with carefully optimized thickness of CsF,and insertion of PVK layer in the PFO-SeBT1/anode interface.Efficient improvement of electron injection of CsF/Al cathode and blocking effect of PVK to electrons were proposed to be responsible for the improved performances of the device.