Open AccessPerformance improvement of polymer light-emitting diodes based on fluorene copolymer with cesium fluoride/aluminum cathode
Author(s) -
Rong Tian,
Ran Yang,
Junbiao Peng,
Yong Cao
Publication year - 2007
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.56.2409
Subject(s) - cathode , materials science , anode , electroluminescence , work function , copolymer , fluorene , diode , optoelectronics , electrode , polymer , light emitting diode , oled , aluminium , electron , layer (electronics) , composite material , chemistry , physics , quantum mechanics
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.