Optical properties of N,N′-bis(3-phenoxy-3-phenoxy-phenoxy)-1,4,5,8-naphthalene-tetracarboxylic diimide by spectroscopic ellipsometry

Optical properties of N,N′-bis(3-phenoxy-3-phenoxy-phenoxy)-1,4,5,8-naphthalene-tetracarboxylic diimide were investigated using variable angle spectroscopic ellipsometry in the visible light range. An oscillator model with one Tauc–Lorentzian and three Gaussian oscillators was constructed and found physically consistent with the experimental results. No measurable optical anisotropy is found in-plane or out of the film plane, indicating a random arrangement of molecules in spin cast thin films. Refractive index n and absorption index k are reported in the 1.5–4.5 eV (840 nm to 280 nm) optical range.