title: Dielectric Effects at Organic/Inorganic Interfaces in Nanostructured Devices.
abstract: Dielectric interfaces are important in organic electronic devices, as they dominate charge generation and recombination dynamics and set the tone for efficiency of the device. In a charge separation scenario across the interface, we calculate the binding energy of a charge carrier for variations in dielectric mismatch (i.e., the ratio of the dielectric constant of materials forming the interface), interface shape and size, and dielectric anisotropy. We find that dielectric mismatch results in binding of the charge carrier to the interface with energies on the order of several kT. For the variation in interface shape and size, epitomized by the device morphology, we show that the assumption of a planar interface overestimates the attractive potential. The change in the interface curvature affects the binding energy of the charge carrier by order of kT. Anisotropy is shown to affect critically the electric field along the principal axis, while the binding energy of the charge is altered by more than 5 kT. We are able to give an upper limit on the change in the binding energy for the variations in the above interfacial factors. These limits can serve as guidelines for optimization, interface engineering, and design of high efficiency organic electronic devices.
authors.affiliation: Photophysics and Optoelectronics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
authors.forename: Tejas S
authors.initials: TS
authors.lastname: Sherkar
authors.affiliation: Photophysics and Optoelectronics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
authors.forename: L Jan Anton
authors.initials: LJ
authors.lastname: Koster
keywords: anisotropy; binding energy; curvature; dielectric; hybrid; organic