| 초록 |
Researchers showed that bottom contact device performance can be improved by modifying Au electrode with self-assembled monolayer but it is not clear why better performance was observed although alkanethiol SAM modified electrode has much lower work function than non-treated electrode. Through ultra-violet photoemission spectroscopy in-situ experiment, we report that 0.69eV energy barrier between decanethiol treated Au electrode and pentacene is observed, which is 0.17eV smaller than the energy barrier of non-treated gold electrode despite decanethiol treated Au electrode has 0.71eV lower work function. This smaller energy barrier is caused by two. One is absence of interface dipole, which is normally observed organic molecules deposited on metal, and the other is different energy structure from different crystallinity. As a result, OFET device with SAM modified electrode which has even lower work function than non-treated electrode shows lower threshold voltage and higher mobility. |
