Photobleaching and single molecule detection of a phosphorescent organometallic iridium(III) complex

We report single molecule detection of phosphorescence from an organometallic complex, tris(2-phenylpyridine)-iridium. The photostability of bulk samples in polymer films is examined by measuring photobleaching kinetics under intense laser irradiation. On a single molecule level, the complex is characterized by phosphorescence time traces, distribution of phosphorescence intensity levels and by polarization modulated excitation.