Multi-layered organic light-emitting diode fabrication using low molecular weight materials by electrospray method

Active technology development efforts to improve the productivity of organic light emitting diode (OLED) fabrication using wet processes based on ink-jet technology have been conducted by taking advantage of the low cost and large area processability of organic materials. However, OLEDs formed by conventional wet processes have been unable to reproduce the high performance levels of OLEDs that were mass-produced by dry processes based on vacuum deposition. We have therefore focused on the electrospray (ES) method as a potential fabrication technology. In this paper, we report on a multilayer thin-film fabrication process with low molecular-weight materials using an ES method that allows atomization of the organic materials by Coulomb repulsion and successive adhesion of solid-state multi-layered thin films. We demonstrate OLED fabrication by this ES method and the characteristics of the resulting devices.