Tuning the color emission of thin film molecular organic light emitting devices by the solid state solvation effect

We demonstrate a general method for tuning the luminescent emission spectru m of dipolar molecules by adjusting the strength of intermolecular dipole-d ipole interactions using a doped guest-host molecular organic thin film sys tem. Spectral shifting is achieved by introducing dopants that change the l ocal electric field in the film. This 'solid state solvation effect' is use d to continuously tune, by up to 75 nm, the peak emission wavelength of org anic light emitting devices consisting of triarylamine host materials doped with polar luminescent dyes DCM2, aluminum tris(8-hydroxyquinoline), or bo th. Red, orange, yellow, green, blue, and white emission is demonstrated wi th the same set of organic molecules. (C) 1999 Elsevier Science B.V. All ri ghts reserved.