Enhancement of Hole Injection from Electrode to Liquid-Crystalline Semiconductor by Chemical Modification of Interfaces

Abstract

The current voltage characteristics of a liquid-crystalline semiconductor 2-(4'-Octypheny1)-6-dodecyloxynaphthalene (8-PNP-012) with various electrodes was measured and analyzed to study the hole injection from the electrodes to 8-PNP-012. It was found that the hole injection was depressed by the dipoles formed between electrodes and 8-PNP-012 when they were in contact with each other. The modification of the surface of an Au electrode with a dipolar self-assembled monolayer (4-nitrophenylthiolate) could significantly enhance the hole injection.