Birefringence and light emission from the polymer LED

Many thin film emissive devices use polymeric materials to produce the opti cal output. The long chain molecular structure of typical polymer materials , and the way in which thin layers of the material are produced in light-em itting devices, often results in a significant difference in the optical pa rameters in directions perpendicular and parallel to the layer. We use a cl assical model to investigate spontaneous emission from such anisotropic mat erials in planar multi-layer structures. By comparing the results of this m odel with those for which the emissive material is assumed to be isotropic, we highlight those performance aspects for which the anisotropy is importa nt. (C) 2000 Elsevier Science S.A. All rights reserved.