Phosphorescent emission of organic molecular chromophores was assigned to the triplet excited state by Lewis and Kasha in 1946.<sup>1</sup> Triplet excited states (excitons) play an important role in current applications of organic materials. For example, in organic light emitting diodes, harvesting of triplet excitons by heavy metal complexes or TADF emitters affords a substantial enhancement in external quantum efficiency and luminous efficiency. In organic solar cells, recombination to produce triplet states can reduce the efficiency of photocurrent generation. Our research program has explored the properties of triplet excitons in pi-conjugated polymers and model oligomer systems. This work has taken advantage of the effect of spin-orbit coupling enhancement by heavy metal centers that are strongly coupled to the pi-conjugated electronic system. In particular, platinum(II) acetylides and orthometalled platinum(II) complexes give rise to enhanced intersystem crossing efficiency and in some cases room temperature phosphorescence. This allows facile investigation of the energetics and dynamics of triplet exciton states. Topics of interest include triplet excited state structure and delocalization in conjugated molecules, the effect of electronic structure on intersystem crossing efficiency, triplet exciton diffusion length, triplet states in organic solar cells and in light emitting diodes.

Conjugated organometallic chromophores and polymers: Properties and applications in organic electronics

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.