When STS of the film is ‘1’ as an ideal film,

it has 100% visible transmittance and 0% near-infrared transmittance. Therefore, this study attempted to obtain a factor that affects the performance see more of the film of highest selectivity with an STS approaching ‘1’. Figure 2 Spectral profiles from solar irradiance and that passing through the film fabricated by double layer coating method. (1) As in the brief illustration provided in Figure 1, a total light transmission and shielding (LTS) function (T total) from the visible to near-infrared regions has been proposed by summing the optical absorption and reflection-induced contribution terms using a tungsten bronze compound-based film. The contribution from the optical absorption of the film (T absorption) was determined using the Mie-Gans LSPR theory. The scattering reflection (T scattering) by the nanoparticles in the coated layer and reflection (T multilayer) based on differences of refractive index between the layers were included. The LTS function is provided

in Equation 2. The factors required selleck by various models have been quantitatively measured and are listed in Table 1. Table 1 Parameters used for calculating optical shielding property of the coated film Thickness of the coated layer [nm] Distance between nanocrystals [nm] Mean diameter of nanocrystals [nm] Dielectric constant of medium Refractive index of the coating layer Refractive index of the nanocrystals Refractive index of PET substrate 5,270 7.19 39.70 8.63 1.47 2.1 1.58 (2) Incident light absorption by the LSPR old According to the Mie-Gans theory [9, 17, 18], the absorption behavior of oval particles in solution is based on a dipole

approximation. Thus, the absorption characteristics of N particles in a volume V against a film of a given thickness (L) according to the wavelength (λ) of incident light can be explained by Equation 3 as follows: (3) The thickness has been set using statistical image analysis of the measurement results obtained via SEM with image J software. In addition, ϵ m, ϵ 1, and ϵ 2 refer to the dielectric constant of each medium, the real number term, and the imaginary number term in the dielectric function, respectively, and can be derived as follows: (4) The parameters for each incident light frequency (ω), volume plasma frequency (ω p), and collision frequency (γ) are closely related to the number density (ϱ) and conductivity (ζ) of the free electrons and were computed using Equations 5 and 6 as follows: (5) (6) in which τ, ϵ 0, and m e are the scattering time for the electrons, the transmittance under vacuum conditions, and the effective electron mass, respectively. The number density of free electrons is a property intrinsic to a given material and is calculated using in which V cell is the unit cell volume of the Cs0.33WO3 nanoparticle. As indicated in Figure 3, the unit cell dimensions of α and β axes were 0.74 and 0.76 nm, respectively.