2 nm and (b) 1.8 nm. Figure 3 shows the SEM micrographs of Ag2/ITO/Ag and Ag3/ITO/Ag multilayer films. As shown in Figure 3a, the Ag nanoparticles are spherical and uniformly distributed in

ITO films. The size of Ag nanoparticle is 5 to 60 nm. With increasing thickness of the Ag surface layer, randomly connected Ag network also appears, as shown in Figure 3b. Figure 3 SEM micrographs of Ag/ITO/Ag multilayer films: (a) Ag2/ITO/Ag and (b) Ag3/ITO/Ag. Figure 4 shows a cross-sectional SEM micrograph of Ag3/ITO/Ag multilayer film. The Ag surface layer, ITO interlayer, and Ag CHIR-99021 mw bottom layer forming the sandwich structure multilayer film have been observed clearly. From Figure 4, it has been seen that the Ag surface layer and bottom layer AZD8931 price have a spherical cluster structure, and the interlayer of ITO film has a columnar structure. Figure 4 Cross-sectional SEM micrograph of Ag3/ITO/Ag multilayer film. Optical properties Figure 5 shows the thickness-dependent transmittance spectra of the multilayer films changing wavelength from 300 to 900 nm. Compared with the bare ITO, the sandwich structure films have lower optical transmittance. It is suggested that the island structure of the thin Ag surface layer makes its transmittance low due to the

large islands and the defects scattering incident light [9, 13]. With the increase of Ag surface layer thickness from 3.0 to 12.6 nm, the transmittance Dinaciclib cost of the multilayer films decreases, which is caused by the changes of the Ag surface layer first from a stable nuclei stage to randomly connected Ag island stage then to Ag network stage. Besides, Ag1/ITO/Ag, Ag2/ITO/Ag, and Ag3/ITO/Ag have low optical transmittance at about 500 nm. Ag4/ITO/Ag has low optical transmittance at about 450 and 550 nm. It is due to the surface plasmon resonance characterization PLEKHB2 of Ag. Figure 5 Transmittance spectra of Ag/ITO/Ag multilayer films. Figure 6 shows the reflectance

spectra of the ITO and multilayer films. Based on Figure 6, it can be observed that multilayer Ag/ITO/Ag films show higher reflectivity than pure ITO film due to the high reflectivity of Ag. Table 1 calculated the average reflectance of the bare ITO and multilayer films. When the thickness of the Ag surface layer increases from 3.0 to 12.6 nm, the microstructure and surface morphology of the Ag surface layer changes a lot; the decrease of holes and defects in the films reduces the energy loss of light and the absorption of multilayer film, so the average reflectance of multilayer films increases from 22.04% to 31.12%. Besides, there is an interference phenomenon in the reflectance spectra of Ag1/ITO/Ag, Ag2/ITO/Ag, and Ag4/ITO/Ag; this will lead to uneven reflection and affect the quality of the LCD. The reflectance spectra of Ag3/ITO/Ag are relatively flat and can eliminate the influence of the interference phenomenon. Figure 6 Reflectance spectra of the ITO and Ag/ITO/Ag multilayer films.