Abstract
The invention proposes a method for preparing an organic light emitting diode and a device thereof, the method comprising providing a substrate on a carrier; distributing a second organic molecule solvent on the substrate wherein the second organic molecule is dissolved in the solvent; coating by a scrape knife the second organic molecule solvent onto the substrate surface to form a wetting film layer; and heating the wetting film layer by a heating unit to remove the solvent and form a second organic molecule film layer, thereby providing a smooth multiple-layered structure suitable for use with large-scale optical elements.