Abstract
Electronic structures of evaporated films of five organic light-emitting and carrier-injecting materials for organic electroluminescent devices were studied by ultraviolet photoemission spectroscopy. The compounds examined were (i) light-emitting materials tris(8-hydroxyquinolino) aluminum (Alq3) and 1,2,3,4,5-pentaphenylcyclopentadiene, (ii) a hole-injecting material N,N′ -bis(3-methylphenyl)-N ,N′ -diphenyl-[1,1′ -biphenyl]-4,4′ -diamine, and (iii) electron-injecting materials N,N′ -diphenyl-1,4,5,8-naphthyletracarboxyldiimide and 1,3,5-tris(5-phenyl-1,3,4-oxadiazol-2-yl)benzene. The spectral features corresponding to the top parts of the valence states, which dominate the electric properties of the materials, were assigned by the comparison with the simulated density of states obtained from PM3 molecular orbital calculations. Using these calculations, the evolution of the electronic structure of each molecule from those of constituent parts was discussed. The characters of the unoccupied states obtained by these calculations were also presented. Using these data, the correlation between the ionization threshold energies determined by ultraviolet photoemission spectroscopy and the carrier-injecting and light-emitting properties were discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 4928-4938 |
| Number of pages | 11 |
| Journal | Journal of Applied Physics |
| Volume | 83 |
| Issue number | 9 |
| Publication status | Published - May 1 1998 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physics and Astronomy (miscellaneous)
Cite this
Electronic structures of organic molecular materials for organic electroluminescent devices studied by ultraviolet photoemission spectroscopy. / Sugiyama, Kiyoshi; Yoshimura, Daisuke; Miyamae, Takayuki; Miyazaki, Takafumi; Ishii, Hisao; Ouchi, Yukio; Seki, Kazuhiko.
In: Journal of Applied Physics, Vol. 83, No. 9, 01.05.1998, p. 4928-4938.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Electronic structures of organic molecular materials for organic electroluminescent devices studied by ultraviolet photoemission spectroscopy
AU - Sugiyama, Kiyoshi
AU - Yoshimura, Daisuke
AU - Miyamae, Takayuki
AU - Miyazaki, Takafumi
AU - Ishii, Hisao
AU - Ouchi, Yukio
AU - Seki, Kazuhiko
PY - 1998/5/1
Y1 - 1998/5/1
N2 - Electronic structures of evaporated films of five organic light-emitting and carrier-injecting materials for organic electroluminescent devices were studied by ultraviolet photoemission spectroscopy. The compounds examined were (i) light-emitting materials tris(8-hydroxyquinolino) aluminum (Alq3) and 1,2,3,4,5-pentaphenylcyclopentadiene, (ii) a hole-injecting material N,N′ -bis(3-methylphenyl)-N ,N′ -diphenyl-[1,1′ -biphenyl]-4,4′ -diamine, and (iii) electron-injecting materials N,N′ -diphenyl-1,4,5,8-naphthyletracarboxyldiimide and 1,3,5-tris(5-phenyl-1,3,4-oxadiazol-2-yl)benzene. The spectral features corresponding to the top parts of the valence states, which dominate the electric properties of the materials, were assigned by the comparison with the simulated density of states obtained from PM3 molecular orbital calculations. Using these calculations, the evolution of the electronic structure of each molecule from those of constituent parts was discussed. The characters of the unoccupied states obtained by these calculations were also presented. Using these data, the correlation between the ionization threshold energies determined by ultraviolet photoemission spectroscopy and the carrier-injecting and light-emitting properties were discussed.
AB - Electronic structures of evaporated films of five organic light-emitting and carrier-injecting materials for organic electroluminescent devices were studied by ultraviolet photoemission spectroscopy. The compounds examined were (i) light-emitting materials tris(8-hydroxyquinolino) aluminum (Alq3) and 1,2,3,4,5-pentaphenylcyclopentadiene, (ii) a hole-injecting material N,N′ -bis(3-methylphenyl)-N ,N′ -diphenyl-[1,1′ -biphenyl]-4,4′ -diamine, and (iii) electron-injecting materials N,N′ -diphenyl-1,4,5,8-naphthyletracarboxyldiimide and 1,3,5-tris(5-phenyl-1,3,4-oxadiazol-2-yl)benzene. The spectral features corresponding to the top parts of the valence states, which dominate the electric properties of the materials, were assigned by the comparison with the simulated density of states obtained from PM3 molecular orbital calculations. Using these calculations, the evolution of the electronic structure of each molecule from those of constituent parts was discussed. The characters of the unoccupied states obtained by these calculations were also presented. Using these data, the correlation between the ionization threshold energies determined by ultraviolet photoemission spectroscopy and the carrier-injecting and light-emitting properties were discussed.
UR - http://www.scopus.com/inward/record.url?scp=0032074213&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032074213&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0032074213
VL - 83
SP - 4928
EP - 4938
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 9
ER -