Fabrication of highly efficient resonant structure assisted ultrathin artificially stacked Ag/ZnS/Ag multilayer films for color filter applications

Abstract

We introduce a novel strategy for the fabrication of mechanically and thermally stable highly efficient resonant structure assisted ultrathin artificially stacked Ag/ZnS/Ag multilayer films on cleaned glass substrates using the thermal evaporation technique. The application of fabricated color filters has been studied in the visible range. These multilayers have good adhesion to each other and to the glass substrate, resulting in mechanical and thermal stability. The stability has been examined by the ''Scotchtape'' test and the ultrasonication process at 37 kHz frequency and at 40 1C temperature as well as by thermogravimetric analysis (TGA). The results of the structural analysis, surface morphology and atomic force microscopy of these filters confirm the good crystallinity with a low value of surface roughness.The effect of thickness of artificially stacked metal (Ag) and dielectric (ZnS) layers has been examined in terms of optical properties by several spectroscopic techniques. These ingenious filters exhibit a large and deep stop band in the visible wavelength region. Thus blue, green and red color filters, centered at 460, 540 and 620 nm having bandwidths of about 25, 44 and 35 nm, respectively, were achieved. Moreover, the statistical outcomes of all the three filters (blue, green and red) show that the peak transmission efficiencies are consistently 73%, 70% and 63%, respectively. Additionally, the effect of different angles of incidence on the transmittance spectra has also been presented. Hence, the obtained results strongly suggest that these filters can be potentially used for tuning the color of optical filters according to the desired applications.

Structural and Optical Characterization of ZnS Ultrathin Films Prepared by Low-Temperature ALD from Diethylzinc and 1.5-Pentanedithiol after Various Annealing Treatments

“…Similar reflectance minimums were observed for the ZnS/Au/Ti multilayer structure deposited on the Si substrate [40] and in electrodeposited ZnS thin films after annealing treatments [41]. Moreover, a significant transmittance of ~70% at around 540 nm [42] and ~90% at around 550 nm [43] was observed for the ZnS layer thickness of 64 and 40 nm, respectively. The broad minimum at around 500 nm in the reflectance spectra of un-annealed ZnS was most probably related with the absorption of the light by Zn 2+ ions [44,45,46,47].…”

Highly conductive and flexible color filter electrode using multilayer film structure

“…Although the thicknesses of the Ag layers were fixed in this study, the sheet resistance and transmittance of CFE could be altered by adopting different Ag thicknesses ( Supplementary Figure 1 , Supplementary Figure 2 , Supplementary Table 1 ). The filtered color can be altered by varying the thickness of the dielectric layer located between two metal layers because of the cavity resonance 14 25 26 27 28 . Moreover, higher transmittance can be obtained by optimizing the layer thickness of the outer layer, which is located at the outside of the metal layer because this layer provides anti-reflection 15 22 29 .…”

“…In efforts to solve these problems, many studies on optical color filters have been conducted. Plasmons from metallic nanostructures are used to make optical color filters 4 5 6 7 8 9 10 , and guided mode resonance is one of the ways used to implement optical color filters 11 12 13 14 15 . An electrode is another important element of optical devices and electronics.…”

Dual-Material Metastructure for Simultaneous Filtering and Focusing of Incoherent White Light

“…The structural parameters such as the height h, spacing p, bottom radius R, and top radius r of the nanocones were adjusted to tune transmission. Different from typical color-filtering methods using dyes, 31 metallic or semiconductor nanoparticles, 32 or multilayer diffractive stacks made of thin films, 33 the transmission color filters based on the nanocone array took advantage of 3D DLW using TPP photoresist with ease of mask-free, high-resolution, and arbitrary geometries. Such features enabled facile color filtering through wavelengthdependent diffraction into higher orders of magnitude to achieve the desired transmission profiles.…”