Date: Tuesday, September 29, 2015
Time: 11:00 am
Speaker: Kirk Schanze, University of Florida
Title: Triplet States in Organometallic Conjugated Materials
Location: 67-3111 Chemla Room
Triplet excited states (excitons) play an important role in the application of organic materials. For example, in organic light emitting diodes, harvesting of triplet excitons 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 π-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 π-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 near-infrared light emitting diodes.