Solubility characteristics of luminescent materials for organic light emitting diodes

Abstract

Organic light emitting diodes (OLED’s) have the potential to be as efficient as inorganic LED’s but significantly cheaper to fabricate. Before these devices can be considered as complete replacements for LED’s, some problems with efficiency loss and degradation must be addressed. Here, we intend to address phase separation and problems it exacerbates,such as triplet-triplet annihilation and polaron-triplet quenching. We hope to address phase separation through manipulation of the solubility properties of the OLED emissive layer materials. We use Hansen Solubility Parameters, which describe solubility for materials in such a way that we can determine the best solvent for a given solute. The current tests for these parameters are not practical for these materials, so we have developed a new procedure for measuring the solubility properties of luminescent materials and used this procedure to test four common OLED materials. The data these tests produced is not precise enough at this time to draw any definitive conclusions about these materials’ solid-solubility.