UV-Vis and near-IR spectra of solid Npe, TCNB, TCNQ, Npe:TCNB, and Npe:TCNQ were acquired in diffuse reflectance mode using a Perkin-Elmer Lambda 1050+ spectrophotometer. Samples were finely ground and mixed with MgO powder (∼40 μm particle size) to make ∼1 wt.% mixtures. Sample mixtures were then pressed against a CaF2 window mounted onto the side of a 100 mm integrating sphere.