HOU Lin-tao, WANG Ping, LIU Peng-yi, ZHANG Jing-lei, WU Chun-hong, LI Yan-wu, WU Bing. A Novel Electron Injection Layer with Co-evaporating Tris (8-hydroxyquinoline) Aluminum Doped Cesium Carbonate in Organic Light-emitting Diodes[J]. 发光学报, 2010,31(5): 655-660
HOU Lin-tao, WANG Ping, LIU Peng-yi, ZHANG Jing-lei, WU Chun-hong, LI Yan-wu, WU Bing. A Novel Electron Injection Layer with Co-evaporating Tris (8-hydroxyquinoline) Aluminum Doped Cesium Carbonate in Organic Light-emitting Diodes[J]. 发光学报, 2010,31(5): 655-660DOI:
A Novel Electron Injection Layer with Co-evaporating Tris (8-hydroxyquinoline) Aluminum Doped Cesium Carbonate in Organic Light-emitting Diodes
The electron injection mechanism of the effective cathode structure has been investigated
doping cesium carbonate (Cs
2
CO
3
) into the organic electron-transport layer
which significantly enhances the electron injection in comparison with an ultra-thin Cs
2
CO
3
injection layer
with a notable superiority in both luminance and efficiency. The results show that Cs
2
CO
3
doped tris-(8-hydroxyquinoline) aluminum(Alq
3
) /Al cathode exhibits better electron injection efficiency than that in Cs
2
CO
3
/Al bilayer cathode
thus a maximum current efficiency of 6.5 cd/A (3.1 cd/A for Cs
2
CO
3
/Al) is obtained for 30% Cs
2
CO
3
doping concentration device. It is proposed that this improved efficiency is related to the greatly enhanced electron injection at the Alq
3
∶ Cs
2
CO
3
/Al cathode interface and efficient electron transport in the bulk of the Cs
2
CO
3
∶ Alq
3
layer. The result from atomic force microscopy shows that with the insertion of Alq
3
∶ Cs
2
CO
3
layer
the roughness of Alq
3
surface decreases
which is favorable to improve the device luminance and increase the device lifetime.
关键词
Keywords
references
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