Spectroscopic Ellipsometry.

Film thickness and anisotropy were extracted from spectroscopic ellipsometry using a J.A. Woollam Co., Inc., M2000 instrument, performed on thin films on Si substrates. Incident angles of 50°, 60°, and 70° were used with 2 s exposure times. Full Mueller Matrix data were collected with the coating director at 0°, 45°, and 90° relative to the incident beam. A biaxial optical model with parametrized absorption spectra was fitted to the rotation scan data, yielding both film thickness and a dichroic ratio at 700 nm. Full model parameters and fitting results can be found in the Supporting Information, Section S1.