Energy structures and chemical reactions at the Al/LiF/Al q3 interfaces studied by synchrotron-radiation photoemission spectroscopy
Journal
Applied Physics Letters
Journal Volume
87
Journal Issue
21
Pages
1-3
Date Issued
2005
Abstract
The chemical properties and energy levels of Al∕LiF∕Alq3 were investigated via high-resolution synchrotron-radiation photoemission spectroscopy. No clear chemical reaction was found with LiF deposited on Alq3. The core-level spectra show that Li+ ion and Alq3 anion are created only after Al is deposited on LiF∕Alq3 surfaces. Combined with the increase of the electron concentrations indicated by the Fermi-level position in valence-band spectra, the results provide direct evidence of the proposed chemical reaction, 3LiF+Al+3Alq3→AlF3+3Li+Alq3−, which leads to the excellent electron injection efficiency in Al∕LiF∕Alq3.
SDGs
Type
journal article