Painting Method for Organic Electroluminescent Devices

A painting method for organic electroluminescent devices using the ink-brush or the felt-coating method is investigated. The merits of this fabrication method include easy production for large-area fabrication and simple and uniform film formation. A maximum luminance of 3,680 cd/m2 is obtained for single-layered and C6-doped PVCz-based devices. Mean roughnesses of 2.3 and 2.0 nm are obtained for ink-brush and felt-coating methods, respectively. The dual-painting method with the polyethylenedioxy thiophene buffer layer is investigated and a lower operational voltage is realized. A white emission using complementary colors of 4-dicyanomethylene-6-cp-julolidinostyryl-2-tert-butyl-4H-pyran (red) and perylene (blue) is also examined.