Directional and ultrafast migrations of excitons/biexcitons in organic polymers by utilizing a local nonuniform electric field

Abstract

In organic devices, migration dynamics of different excited states (e.g., excitons and biexcitons) are of vital importance to their functional processes. Here, by utilizing a local nonuniform electric field to organic polymers, a new strategy to manipulate the directional and ultrafast migrations of both excitons and biexcitons has been theoretically reported. In particular, it is found that the direction of migration of biexcitons is opposite to that of excitons. The underlying mechanism is attributed to the reverse polarized behavior of excitons and biexcitons, on which reverse driving forces are separately created to act. Furthermore, to confirm and apply these theoretical findings, an experimental scheme is devised, aiming at luminescence modulation by manipulating the ultrafast redistribution of preformed excitons or biexcitons in an organic luminescent layer. The ranges of response time and visual resolution for the luminescence modulation have also been discussed.