LIGHT IMAGE FORMATIONS ON DEPROTONATED POLYANILINE FILMS CONTAINING TIO2 PARTICLES

Formation of novel light images of high resolution in polyaniline film s containing TiO2 particles is described. The light images are produce d by scanning the third harmonic of a Nd:YAG laser on the polyaniline films or by exposing the polyaniline films to lights from a xenon lamp through patterned masks. The keys for the light image formation are ( 1) to incorporate the semiconductor particles into polyaniline, (2) to convert highly conductive polyaniline into insulating one by utilizin g deprotonation which is induced to occur by immersing the conducting polyaniline in aqueous neutral solutions or by anodically polarizing i n aliphatic alcohol solutions such as methanol and ethanol solutions, and (3) to use a hole scavenger capable of releasing protons on its ox idation such as above alcohols. The quantum efficiency for the light i mage formation determined at 355 nm under a low illumination intensity was ca. 10%. The mechanisms of the formation of light images are disc ussed.