DEGRADATION OF POLYMER-BASED LIGHT-EMITTING-DIODES DURING OPERATION

Segmented block copolymers consisting of conjugated-nonconjugated sequ ences an useful chromophores in polymer LEDs and can lead to efficient devices of high luminance. The lifetime of such diodes depends on num erous chemical and physical interactions. Some of these pertaining to the chromophore/electrode interface can be usefully studied by optical and various electron microscopies. Zn typical diodes studied here, fa ilure is associated inter alia with irregularities in the spin-coated polymer films. Atomic force microscopy provides a more detailed examin ation of the morphology of the polymer films. (C) 1997 Elsevier Scienc e S.A.