[XPS spectra of Langmuir-Blodgett films and their electroluminescence].
The coordination of monolayer of amphiphilic ligands, N, N-bis(8-quinolinyl)alkyl propanediamide, H2A(alkyl = dodecyl, H2A12; hexadecyl, H2A16) with Cu2+ at air-water interface was investigated by X-ray Photoelectron Spectroscopy (XPS) and UV-Vis spectra. The collapse pressure of the monolayers of H2A12 and H2A16 increased from 12.5 and 15.6 mN x m(-1) to 28.0 and 33.8 mN x m(-1) after their coordination with Cu2+ ions, respectively. XPS indicated that the coordination ratio between H2A and Cu2+ was 1:1. The binding energies of Cu2p were 935 and 955 eV. The Langmuir-Blodgett(LB) films of H2A12 and H2A16 can be used as transporting materials in three-layer electroluminescence devices: ITO/TPD/LB films/Alq3/Al. The driving voltages were 6.5 and 7.5 V, the maximum luminances were 621 and 201 cd x m(-2), respectively.
Ouyang
Jian-ming
JM
Department of Chemistry, Ji'nan University, Guangzhou 510632, China.
Bai
Yu
Y
Yu
Gui
G
Wang
Shi
S
Liu
Yun-qi
YQ
Li
Yong-fang
YF
Zhu
Dao-ben
DB