Solution Processed Multilayer Organic Light Emitting Diodes
To date, most commercially available organic light emitting diodes (OLED) are fabricated by cost extensive and material-consuming thermal vacuum deposition processes. Therefore, a switch to a solution-based fabrication strategy, albeit challenging for efficient multilayer designs, is highly desirable. The necessity for multilayer device architectures is comprehensively explained at the beginning of the chapter and the challenges arising in a solution-based process are explained. The remainder of the chapter is dedicated to the presentation of the different fabrication schemes. First, schemes that allow for the fabrication of multiple layers from the same solvents without a modification of the used organic semiconductors are detailed. Subsequently, schemes that use the same solvents but also require an alteration of the organic semiconductor are presented. Furthermore, fabrication of multiple layers from different solvents is explained. At the end a few notable approaches that combine different fabrication mechanisms are detailed. For each scheme presented within this chapter references to the literature are provided.