Unified model for singlet fission within a non-conjugated covalent pentacene dimer

作者：Basel Bettina S; Zirzlmeier Johannes; Hetzer Constantin; Phelan Brian T; Krzyaniak Matthew D; Reddy S Rajagopala; Coto Pedro B; Horwitz Noah E; Young Ryan M; White Fraser J; Hampel Frank; Clark Timothy; Thoss Michael; Tykwinski Rik R; Wasielewski Michael R; Guldi Dirk M

来源：Nature Communications, 2017, 8(1): 15171.

DOI：10.1038/ncomms15171

When molecular dimers, crystalline films or molecular aggregates absorb a photon to produce a singlet exciton, spin-allowed singlet fission may produce two triplet excitons that can be used to generate two electron-hole pairs, leading to a predicted similar to 50% enhancement in maximum solar cell performance. The singlet fission mechanism is still not well understood. Here we report on the use of time-resolved optical and electron paramagnetic resonance spectroscopy to probe singlet fission in a pentacene dimer linked by a non-conjugated spacer. We observe the key intermediates in the singlet fission process, including the formation and decay of a quintet state that precedes formation of the pentacene triplet excitons. Using these combined data, we develop a single kinetic model that describes the data over seven temporal orders of magnitude both at room and cryogenic temperatures.

• 出版日期2017-5-18