LUMINESCENCE EFFICIENCY AND TIME-DEPENDENCE IN A HIGH ELECTRON-AFFINITY CONJUGATED POLYMER

We report measurements of the efficiency and time dependence of photol uminescence in a high electron affinity cyano-substituted derivative o f poly (p-phenylenevinylene). In solution the photoluminescence quantu m yield is 0.52 +/- 0.05, and the luminescence lifetime is 0.9 +/- 0.1 ns. In solid films the luminescence quantum yield is 0.35 +/- 0.03 an d the luminescence lifetime, of 5.6 +/- 0.2 ns, is much longer. These results strongly suggest that the emission from the film is from an in ter-chain excitation, and that inter-molecular interactions are an imp ortant factor to consider in the design of highly luminescent conjugat ed polymers.