Emission Spectra of Phthalocyanine Crystals

The emission spectra of phthalocyanine single crystals and evaporated films were investigated in the near infrared. In a H 2 Pc single crystal, several fluorescence peaks were observed between 760 mµ∼1 µ. In a CuPu single crystal, one phosphorescence band with fine structures was observed at 1.12 µ. However, no fluorescence was observed between 700 mµ∼1 µ. In ZnPc single crystals, both the fluorescence peaks and the phosphorescence peak at 1.15 µ were observed. In CoPc and NiPc, no emission was observed. These emission spectra were discussed in connection with S-T interaction caused by central metals. The phosphorescence was decreased markedly with raising temperature. In the evaporated film, a fairly broad emission band was observed which was attributed to the excimer emission tentatively. By the thermal treatment of this film, this broad band changes to the emission band of the single crystal.