Full color organic light emitting diodes with laser-patterned optical path-length compensation layer

In this paper, we describe a promising way to fabricate micro-cavity OLEDs (organic light emitting diodes) with the concept of "super top emission" with soluble optical path-length compensation layer (OPCL) formed by Laser Induced Thermal Imaging (LITI) technology. OPCL is an additional layer for setting the cavity length corresponding to intrinsic wavelength of emitter. The resultant OLEDs gave a saturated three primary colors (RGB) after transmitting through common color filters by micro-cavity effect. By this approach, we could simplify the fabrication process of full color OLEDs by reducing conventional color patterning step, fine metal mask method. We also suggested the blending system of polymer and small molecule as transfer layer and this could improve the quality of laser patterning by controlling the surface energy adequately. Also, this system could be a solution to LITI problem of chronic contaminant because transferred materials could remain after cleaning process. Devices fabricated by soluble/LITI process showed comparable or even better performances and the device characteristics could enhance by further study of optimizing several parameters such as materials property and laser patterning condition. Also, we expect that this concept could lead to develop the fabrication process of large and high-resolution OLED displays.