Structural transformation and crystallization of amorphous copper phthalocyanine nanostructures

Vapor condensation was performed to prepare nanostructures of copper phthalocyanine. With a lower pressure and longer evaporation duration, a fine and dense network of thin and uniform nanowires was obtained. Nanorods with tube-like branches were formed at higher working pressures. The absorption coefficients and optical band gaps of the nanostructures were derived from the UV–vis absorption spectra. After heat treatment, the amorphous nanowires were transformed into crystalline straight β-phase nanostructures with a smooth surface. Reduced intensity of the absorption spectrum and a red shift of the optical band gap were also observed.