Vacuum sublimed thin films of copper phthalocyanine were prepared at room temperature. The optical properties of thin CuPc films have been investigated in the spectral range 200-2100 nm. The refractive index n as well as the absorption index k were calculated before and after annealing. It is obvious that the refractive index showed an anomalous dispersion in the absorption region as well as normal dispersion in the transparent region. The analysis of the spectral behavior of the absorption coefficient, α in the absorption region revealed direct transitions. The analysis of α as well as the dielectric constants ε 1 and ε 2 reveals several absorption peaks at photon energies given in the text. The fundamental and the onset energy gaps could also be estimated as 2.74+0.02 and 1.64+0.02 eV respectively.
)
View on SCiNiTO