Using resonance energy transfer to improve exciton harvesting in organic-inorganic hybrid photovoltaic cells

The use of resonance energy transfer (RET) to transport excitons in organic photovoltaic cells from the light-absorbing donor layer to the acceptor layer was discussed. The method places excitons right at the donor/acceptor (D/A) interface, where they can be split by hole transfer. The method is faster than exciton diffusion and enables harvesting of excitons before germinate recombination occurs. The method also provides a mechanism for excitons to overcome low-energy sites in the absorbing layer that could prevent them from diffusing to the D/A interface. It is found that RET strategy is essential to efficiently harvesting excitons in many types of bulk heterojunction PV cells.