Halogen-substituted zinc(II) phthalocyanines: Spectral properties and structure of thin films

In this work, the effect of the type of halogen substituents on the structure, morphology, and conductivity of thin films of zinc(II) phthalocyanines ZnPcHal(4) (Hal = F, Cl, Br, I), deposited both by evaporations in vacuum and by a spin coating technique was studied. The influence of these different halogen substituents on the spectral properties of ZnPcHal(4) derivatives was also investigated. For this purpose, the density-functional theory calculations of the vibrational spectra of ZnPcHal(4) were carried out. It was shown that ZnPcHal(4) (Hal = F, Cl) films obtained by physical vapor deposition (PVD) were polycrystalline and consisted of well-distinguishable rounded grains, whereas the introduction of the bulk bromine and iodine substituents led to the formation of amorphous films both in the PVD process and during spin coating deposition. The lateral d.c. conductivity of the films was shown to decrease in the order ZnPcCl4 > ZnPcF4 > ZnPcBr4 > ZnPcI4. The conductivity of PVD films, which were characterized by higher crystallinity and order, was higher than that of spun films.

Automated summary

This study investigated the influence of different halogen substituents on the structure, morphology, and conductivity of thin films of zinc(II) phthalocyanines. It was found that films obtained by physical vapor deposition exhibited a polycrystalline structure, while films obtained by spin coating were amorphous. The conductivity of the films was shown to be dependent on the type of halogen substituent, with the highest conductivity observed in films with chlorine substituents.