Nanoplasmonic (“Sub-Critical”) Silver as Optically Absorptive Layers in Solar-Control Glasses

Designing Optical Coatings with Incorporated Thin Metal Films

“…These measurements at a thickness of 45 nm are essentially like those of bulk silver. These indices are also similar to those of Willey et al [13] as seen in Figure 2a,b comparing Hernandez, Willey, and Medwick et al [14] Ag films, all films at 10 nm effective thickness. Figure 2a,b also demonstrate that results are influenced by the materials and processes used to deposit the films.…”

“…Of course, when regarding transmittance or reflectance of the silver-coated surface, one has to take into account that the optical response is now defined by the combined effect of the silver film and the seed layer. It appears that a key advantage of the designs reported by Medwick et al [14] is that they have found a combination of materials and processes where the thin silver films (~10 nm) have n-and k-values much like the properties of bulk silver, where the n-values approach zero and the k-values are large.…”

“…The thermal Ag seems to percolate by 15 or 16 nm, whereas the sputtered Ag has nearly the same effect by 4 nm. It appears that a key advantage of the designs reported by Medwick et al [14] is that they have found a combination of materials and processes where the thin silver films (~10 nm) have n-and k-values much like the properties of bulk silver, where the n-values approach zero and the k-values are large.…”

“…Figure 26, derived from the report of Hernandez-Mainet et al [12], are indices to be compared with Figures 18-20 derived from Medwick et al [14]. The silver materials and process of Hernadez do not become fully bulk-like until they are thicker than 30 nm, whereas those of Medwick are nearly bulk-like soon after 6 nm.…”

“…The work reported by Medwick et al [14] will be used as an example of designing Low-E coatings. Figure 17 is reproduced from their Figure 8 showing the solar spectrum and the transmittance of two of Vitro's Low-E products.…”