TY - JOUR
T1 - Processes for high efficiency of organic EL devices with dopants
AU - Yamaguchi, Masaki
AU - Nagatomo, Takao
N1 - Funding Information:
This work was supported in part by a Graint-in-Aid for International Scientific Research Project (No. 09045058), and for High-Tech Research Center Project from Ministry of Education, Science, Sports and Culture, Government of Japan. The Shibaura Institute of Technology assisted in meeting the publication costs of this article.
PY - 2000/3/1
Y1 - 2000/3/1
N2 - Perylene doped poly(9-vinylcarbazole) (PVCz) was used as a light-emitting layer. The difference between the lowest unoccupied molecular orbital (LUMO) of PVCz and the Fermi level of MgAg cathode is 1.9 eV. Therefore, to decrease this potential difference, 2(4′-tert-butylphenyl)-5-(4′-biphenyl)-1,3,4-oxiadiazole (Bu-PBD) and tris(8-hydroxyquinoline) aluminum (AlQ) layers were inserted between PVCz and MgAg cathode. The copper phthalocyanine (CuPc) layer decreases the barrier height between the Fermi level of ITO anode and the highest occupied molecular orbital (HOMO) of PVCz. These electroluminescence (EL) devices have a wide range luminescent spectral from blue to yellow/green colors by varying doping levels of perylene into PVCz. It was clarified that the luminance and efficiency can be improved by the EL cell structure. Our experimental evidence indicates that the dopant concentration and carrier injection balance have an influence on obtaining high luminance and efficiency.
AB - Perylene doped poly(9-vinylcarbazole) (PVCz) was used as a light-emitting layer. The difference between the lowest unoccupied molecular orbital (LUMO) of PVCz and the Fermi level of MgAg cathode is 1.9 eV. Therefore, to decrease this potential difference, 2(4′-tert-butylphenyl)-5-(4′-biphenyl)-1,3,4-oxiadiazole (Bu-PBD) and tris(8-hydroxyquinoline) aluminum (AlQ) layers were inserted between PVCz and MgAg cathode. The copper phthalocyanine (CuPc) layer decreases the barrier height between the Fermi level of ITO anode and the highest occupied molecular orbital (HOMO) of PVCz. These electroluminescence (EL) devices have a wide range luminescent spectral from blue to yellow/green colors by varying doping levels of perylene into PVCz. It was clarified that the luminance and efficiency can be improved by the EL cell structure. Our experimental evidence indicates that the dopant concentration and carrier injection balance have an influence on obtaining high luminance and efficiency.
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U2 - 10.1016/S0040-6090(99)00974-8
DO - 10.1016/S0040-6090(99)00974-8
M3 - Conference article
AN - SCOPUS:0033895924
SN - 0040-6090
VL - 363
SP - 21
EP - 24
JO - Thin Solid Films
JF - Thin Solid Films
IS - 1
T2 - The Asia-Pacific Symposium on Organic Electroluminescent Materials and Devices
Y2 - 8 June 1999 through 11 June 1999
ER -