The characterization of the optical functions of BCP and CBP thin films by spectroscopic ellipsometry

The optical properties of 2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline (bathocuproine or BCP) and 4,4′-bis(carbazol-9-yl)biphenyl (CBP) thin films were characterized by spectroscopic ellipsometry (SE). Thin films of BCP and CBP were evaporated on silicon substrates. Spectroscopic ellipsometry measurements were performed in the wavelength range of 300-1000 nm. The refractive indices and extinction coefficients of BCP and CBP were determined by fitting the obtained data using Lorentz model and Relaxed Lorentz (RL) model with variable thicknesses. The extinction coefficients obtained from the fitting of ellipsometry data were in excellent agreement with absorbance measurement results.