Outside materials used on a building’s exterior must have high transmittance and excellent aesthetic design. The optimum design was achieved in this study by calculating the optical properties and color distribution to fabricate a high-quality multilayer color thin film through sputtering, and a silicon solar panel was equipped with transmissive- and reflective-type color optical thin films. A three-layer color thin film with a Nb2O5/SiO2/Nb2O5 structure exhibited an average transmittance of over 85.96% and a clear blue color. Simultaneously, it maintained a high overall efficiency with a maximum output value greater than 99% of the value of a reference silicon solar cell. Therefore, the sputtered multilayer thin-film coating not only offers a facile approach to manufacture colorful solar panels, but also has great potential for various industrial applications such as building-integrated solar power generation, automobile production, and glass production.

In this study, we synthesized Au nanoparticles (AuNPs) in polyacrylonitrile (PAN) thin films using a simple annealing process in the solid phase. The synthetic conditions were systematically controlled and optimized by varying the concentration of the Au salt solution and the annealing temperature. X-ray photoelectron spectroscopy (XPS) confirmed their chemical state, and transmission electron microscopy (TEM) verified the successful synthesis, size, and density of AuNPs. Au nanoparticles were generated from the thermal decomposition of the Au salt and stabilized during the cyclization of the PAN matrix. For actual device applications, previous synthetic techniques have required the synthesis of AuNPs in a liquid phase and an additional process to form the thin film layer, such as spin-coating, dip-coating, Langmuir-Blodgett, or high vacuum deposition. In contrast, our one-step synthesis could produce gold nanoparticles from the Au salt contained in a solid matrix with an easy heat treatment. The PAN:AuNPs composite was used as the charge trap layer of an organic nano-floating gate memory (ONFGM). The memory devices exhibited a high on/off ratio (over 106), large hysteresis windows (76.7 V), and a stable endurance performance (>3000 cycles), indicating that our stabilized PAN:AuNPs composite film is a potential charge trap medium for next generation organic nano-floating gate memory transistors.