Inspired by a well-studied blue-to-UV UC sensitizer, tris(2-phenylpyridine)iridium(III), Ir(ppy)3 Ir(dmppy-pro)2tmd (tmd) (Fig. ). These two iridium complexes are structurally similar to ppy3, but with drastically improved solubilities in the TCB solvent used for micelle fabrication (Table ). During the micelle fabrication process, upconversion molecules are not dispersed evenly across all micelles; rather, upconversion molecules are dispersed following a Poisson distribution. If solubility in TCB is limited, it is difficult to encapsulate enough sensitizers and annihilators within each micelle to enable TTA-UC. For instance, the solubility of ppy3 in both toluene and TCB is less than 1 mM (Table ). Although this solubility is sufficient for UC in bulk solutions (UC materials dissolved in solvents without nanoencapsulation), much higher solubilities are necessary for encapsulation. Modeling the Poisson distribution of ppy3, ppy2, and tmd based on their solubilities in TCB (Table ), average number of molecules per micelle were predicted to be 3, 28, and 74, respectively (Fig. ). This drastic increase in encapsulation efficiency of ppy2 and tmd suggests their potential to improve UC emission in micelles.