POLARIZATION-DEPENDENT PHOTOCURRENT IN THIN-FILM POLYDIACETYLENE SINGLE-CRYSTALS

Investigations of the anisotropic photocurrent behaviour, as a function of laser intensity and sample temperature, in thin film polydiacetylene single crystals are reported. These polydiacetylenes, PTS (poly-(2,4-hexadiyne-1,6-diol bis(p-toluenesulphonate))) and BTFP (poly-bis-(4-n-butyl-2,3,5,6-tetra-fluorophenyl) butadiyne), have similar one-dimensional electronic band structures. However, the polarization and temperature-dependent photocurrent have completely different behaviour for PTS and BTFP. These results indicate that photocurrent behaviour in these quasi-one-dimensional semiconductors is strongly influenced by the nature and organization of the side groups.