GALLIUM PHTHALOCYANINES - STRUCTURE-ANALYSIS AND ELECTROABSORPTION STUDY

Electroabsorption has been measured with thin films of several (phthal ocyaninato)galliums. It has been observed that the lowest energy absor ption peak of most of the compounds studied is sensitive to the applie d electric field. The shape of the electroabsorption spectrum is well reproduced by the second derivative of the corresponding absorption, i ndicating that the excited state has the character of a charge transfe r state. It has been found that a clear correlation exists between the magnitude of the electromodulation and the sensitivity for the charge carrier generation. Crystal structure analysis of two compounds, hydr oxygallium phthalocyanine type XI and chlorogallium phthalocyanine typ e II, made by Rietveld analysis, clarified that the molecules are stac ked in pairs. The implication of the dimer structure is discussed.