Figure 3
Humidity effect on optical properties. (a) Wavelength-dependent extinction coefficient (k) (top panel) and index of refraction (n) (bottom panel) of CuPcTs film under different RH conditions. (b) Top panel: Optical film thickness as RH is increased (adsorption, black squares) and decreased (desorption, red circles). Lines show exponential fits. Error bars correspond to errors propagated from fitting to the Lorentz oscillator model. Bottom panel: Bandgap energy (Eg) of Q-band (left axis) and B-band (right axis). Straight lines show two roughly linear regimes. (c) Results from PCA analysis of Δ and (d) Ψ obtained from SPE measurements. RH dependence of principal components is shown in main plots with each component’s contribution to the actual spectra shown in the insets. The units of Δ and Ψ are degrees and their principal components are displayed in relative units.
