NOVEL PHOTO-MEMORY EFFECT IN PHOTOCONDUCTIVITY OF CONDUCTING POLYMER CONTAINING PHOTOCHROMIC DYE

Photoconduction of a conducting polymer, poly(9,9-dihexadecylfluorene) containing a photochromic dye, cis- 1,2-dicyano- 1,2-bis(2,4,5-trimethyl-3-thienyl)ethene, is suppressed upon photoisomerization of the dye from ring-open form to ring-closed form but recovered by the reverse photoisomerization. The reversible memory effect in the photoconduction has been discussed on the basis of the energy states of the dye and those trapping effects on the photo-carriers in the conducting polymer.