Solar spectral optical properties of pigments—Part II: survey of common colorants

TitleSolar spectral optical properties of pigments—Part II: survey of common colorants
Publication TypeJournal Article
Year of Publication2005
AuthorsLevinson, Ronnen M., Paul Berdahl, and Hashem Akbari
JournalSolar Energy Materials and Solar Cells
Volume89
Start Page351
Issue4
Pagination351-389
Date Published12/2005
Keywordscool roofs, Kubelka-Munk absorption and backscattering coefficients, Pigment characterization, Solar spectral optical properties, Titanium dioxide
Abstract

Various pigments are characterized by determination of parameters S (backscattering) and K (absorption) as functions of wavelength in the solar spectral range of 300–2500 nm. Measured values of S for generic titanium dioxide (rutile) white pigment are in rough agreement with values computed from the Mie theory, supplemented by a simple multiple scattering model. Pigments in widespread use are examined, with particular emphasis on those that may be useful for formulating non-white materials that can reflect the near-infrared (NIR) portion of sunlight, such as the complex inorganic color pigments (mixed metal oxides). These materials remain cooler in sunlight than comparable NIR-absorbing colors. NIR-absorptive pigments are to be avoided. High NIR reflectance can be produced by a reflective metal substrate, an NIR-reflective underlayer, and/or by the use of a pigment that scatters strongly in the NIR.

DOI10.1016/j.solmat.2004.11.013