抄録
Titanylphthalocyanine (TiOPc) thin films with various crystallinity were prepared by vacuum deposition, changing substrate temperature (Tsub) from -160 to 200°C, and their photoconductivity was examined. Two types of cells with sandwich and surface type electrodes were fabricated for photoconductivity measurements. Surface morphology of the TiOPc films was examined by STM observation, All the TiOPc films deposited at a Tsub of above 20°C were polycrystalline (β-form), and the film crystallinity increased with an increase in the Tsub. But, TiOPc films deposited at low Tsub's were quasi-amorphous or amorphous. Photoconductive sensitivity of the TiOPc thin films increased with a decrease in the Tsub. STM observation indicated that the surface of films deposited at low Tsub's was smooth, while irregular at high Tsub's. A molecular configuration model for the TiOPc films was proposed to explain experimental results on the crystallinity and photoconductivity of the TiOPc films.
