A simple absorber design which enables near-perfect absorption in the visible and near-infrared regions is presented. The absorber is an unpatterned metal/dielectric/metal triple-layer, e.g., a 20 nm-thick metal film as the top layer, a 250 nm-thick dielectric film as the middle layer, and a 200 nm-thick metal film as the bottom layer. It was found that the high-efficiency absorption at specific wavelengths is mainly due to the Fabry-Perot (FP) resonances in the dielectric middle layer which result in trapping of the resonant light in the middle layer and thus enhanced absorption efficiency.

Self-organized TiO 2 nanomaterials grown by anodic oxidation of Ti foils have attracted broad scientific interest due to their wide potential applications. The majority of anodic TiO 2 nanostructures studied to date are in the form of self-ordered nanotube arrays. Here we report an exotic type of multilayered nanoporous TiO 2 films that are conveniently fabricated by anodizing Ti foils of high imperfection levels using a novel multipulse anodization method. The fabricated TiO 2 films feature tens of welldefined layers whose long-range structural periodicity leads to photonic band gaps in the visible wavelengths and vivid film colors. Moreover, the optical responses (or the film color) of the fabricated TiO 2 multilayers not only are sensitive to environmental chemicals but also can be electrically switched on and off repeatedly, demonstrating their novel potential applications for, e.g., colored smart windows or electric display boards.

For following the trend of miniaturization as per Moore's law, increasing efforts have been made to develop single devices with versatile functionalities for Internet of Things (IoT). In this work, organic optical memory devices with excellent dual optoelectronic functionality including light sensing and data storage have been proposed. The Au@Ag core-shell nanorods (NRs)-based memory device exhibits large memory window up to 19.7 V due to the well-controlled morphology of Au@Ag NRs with optimum size and concentration. Furthermore, since the extinction intensity of Au@Ag NRs gradually enhance with the increase in Ag shell thickness, the phototunable behaviors of memory device were systematically studied by varying the thickness of Ag shell. Multilevel data storage can be achieved with the light assistant. Finally, the simulation results demonstrate that the phototunable memory property is originated from the multimode localized surface plasmon resonance (LSPR) of Au@Ag NRs, which is in consistent with the experimental results. The Au@Ag core-shell NRs-based memories may open up a new strategy toward developing high-performance optoelectronic devices.

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A facile electrochemical method to selectively remove the outer walls of anodic TiO2 nanotubes by leaving the as‐anodized nanotubes in the same electrolyte and applying an electric field parallel to the anodic film for several minutes is reported. The better‐separated single‐walled TiO2 nanotubes thus obtained show significantly improved photocatalytic efficiency compared with their non‐etched counterparts.