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P‐107: Very Bright and Efficient Phosphorescent Organic Light‐Emitting Diode with Hole Transport Layer Deposited under Relatively High Pressure
Author(s) -
Qiu Chengfeng,
Peng Huajun,
Xie Zhiliang,
Chen Haiying,
Wong Man,
Kwok HoiSing
Publication year - 2004
Publication title -
sid symposium digest of technical papers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.351
H-Index - 44
eISSN - 2168-0159
pISSN - 0097-966X
DOI - 10.1889/1.1833172
Subject(s) - phosphorescence , dopant , materials science , oled , layer (electronics) , iridium , doping , optoelectronics , diode , phosphorescent organic light emitting diode , analytical chemistry (journal) , optics , chemistry , nanotechnology , fluorescence , organic chemistry , catalysis , physics
The characteristics of an organic light‐emitting diode depend on the deposition pressure of the hole transport layer. This effect and the effect of dopant concentration in the emitting layer were investigated. Diodes were constructed using NPB as hole‐transport layers, phosphorescent fac tris(2‐phenylpyridine) iridium (III) [Ir(ppy) 3 ] doped CBP materials as emitting layer, BCP as hole blocking layer and Alq 3 as an electron injection‐transport layer. The peak efficiencies of the diodes were sensitive to the deposition pressure of the hole transport layer, and to the dopant concentration. With an optimal pressure, an current efficiency of 44Cd/A with 12wt% Ir(ppy) 3 concentration was obtained. A maximum brightness of 210,000 Cd/m 2 (cw) was obtained with 15wt% Ir(ppy) 3 concentration.