ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 39, Number 3
JKCSEZ 39(3)
June 20, 1995 

Metal free phthalocyanine(H2Pc) partially doped with iodine, H2Pc(Ⅰ)x, has been made to improve photosensitizing efficiency of ZnO/H2Pc. The content of iodine dopant level(x) for H2Pc(Ⅰ)x upon H2Pc polymorphs was characterized as χ-H2Pc(Ⅰ)0.92 and β-H2Pc(Ⅰ)0.96 by elemental analysis. Characterization of iodine-oxidized H2Pc were investigated by TGA (thermogravimetric analysis), UV-Vis, FT-Ir, Raman and ESR (electron spin resonance) spectrum, and the adsorption properties of H2Pc(Ⅰ)x on ZnO were characterized by means of Raman ESR studies. TGA for H2Pc(Ⅰ)x showed a complete loss of iodine at approximately 265℃ and Raman spectrum of H2Pc(I)x and ZnO/H2Pc(I)x at 514.5 nm showed characteristic I3- patterns in the frequency region 90∼550 cm-1. ZnO/H2Pc(I)x exhibited a very intense and narrow ESR signal at g=2.0025±0.0005 compared to H2Pc/ZnO. Iodine doped ZnO/H2Pc(I)x showed a better photosensitivity compared to iodine undoped ZnO/H2Pc. That is, the surface photovoltage of χ-H2Pc(I)0.92/ZnO was approximately 31 times greater than that of ZnO/χ-H2Pc and ZnO/β-H2Pc(I)0.96 was 5 times more efficient than ZnO/β-H2Pc at 670 nm. And the dependence of photosensitizing effect upon H2Pc polymorphs was exhibited that the surface photovoltage of ZnO/χ-H2Pc(I)0.92 was approximately 5 times greater than ZnO/β-H2Pc(I)0.96 at 670 nm. Therefore Iodine doping of H2Pc resulted in increase in photoconductivity of H2Pc and photovoltaic effect of ZnO/H2Pc in the visible region.