| abstract |
An organic light emitting structure comprises, in sequence, a substrate, a firstnelectrically conductive layer, a transparent organic light emitting layer structure, a transparentnelectrically conductive metal layer having a work function less than 4 eV, and ansecond electrically conductive layer of indium tin oxide. n The structure can be incorporated in a multicolor organic light emitting devicenemploying vertically stacked layers of double heterostructure devices which are fabricatednfrom organic compounds. The vertical stacked structure is formed on a glassnbase having a transparent coating of ITO or similar metal to provide a substrate. Depositednon the substrate is the vertical stacked arrangement of three double heterostructurendevices, each fabricated from a suitable organic material. Stacking is implementednsuch that the double heterostructure with the longest wavelength is on the topnof the stack. This constitutes the device emitting red light on the top with the devicenhaving the shortest wavelength, namely, the device emitting blue light, on the bottom ofnthe stack. Located between the red and blue device structures is the green devicenstructure. The devices are configured as stacked to provide a staircase profile wherebyneach device is separated from the other by a thin transparent conductive contact layernto enable light emanating from each of the devices to pass through the semitransparentncontacts and through the lower device structures while further enabling each of the devicesnto receive a selective bias. |