Enhanced Bimolecular Recombination of Charge Carriers in Amorphous Organic Semiconductors: Overcoming the Langevin Limit

Abstract

We consider the bimolecular charge carrier recombination in amorphous organic semiconductors having a special kind of energetic disorder where energy levels for electrons and holes at a given transport site move in the same direction with the variation of some disorder governing parameter (the parallel disorder). This particular kind of disorder could be found in materials where the dominant part of the energetic disorder is provided by the conformational disorder. Contrary to the recently studied case of electrostatic disorder, the conformational disorder, if spatially correlated, leads to the increase of the recombination rate constant which becomes greater than the corresponding Langevin rate constant. Probably, organic semiconductors with the dominating conformational disorder represent the first class of amorphous organic semiconductors where the recombination rate constant could overcome the Langevin limit.

28 pages, 4 figures

References in corpus (4)

• Origin of Reduced Polaron Recombination in Organic Semiconductor Devices
• Polaron Recombination in Pristine and Annealed Bulk Heterojunction Solar Cells
• Encounter-Limited Charge Carrier Recombination in Phase Separated Organic Semiconductor Blends
• Bimolecular Recombination of Charge Carriers in Polar Amorphous Organic Semiconductors: Effect of Spatial Correlation of the Random Energy Landscape

Cited by in corpus (1)

• Two-dimensional bimolecular recombination in amorphous organic semiconductors