[Influences of transport layers barriers on recombination efficiency in bilayer organic devices]

Based on the physical processes of carriers transport and recombination, a multi-barriers model for carriers transport and recombination in bilayer organic devices is present. The influences of applied bias and thin films (transport layers) barriers on carriers recombination and its efficiency are calculated and discussed. In bilayer organic devices the charge density inside the sample is controlled by interfacial charge accuulation. Interfacial charge accumulation enhances the field in the cell compartment adjacent to the contact at which minority carrier injected. This gives rise to enhanced minority carriers injection and explains why efficient bilayer organic devices can be fabricated. For appropriate values of anodic and cathodic zone energy barriers, a greater recombination efficiency can be acquired. The theory from this model reasonably explained the experimental phenomens, and it proved that the field can control the carriers recombination regions.