Electrochromic, Surface-Anchored Metal-Organic Frameworks for Stabilized Silver Nanowire Flexible Transparent Electrodes.

Despite excellent optical and electrical properties, the brittleness of indium tin oxide (ITO), used as a transparent electrode, prevents the realization of stable flexible devices. If silver nanowire (AgNW) networks represent a promising alternative, their lack of thermal and electrochemical stability still prevents their fast development in numerous applications. Herein, we report a novel strategy consisting of the deposition of an electrochromic and protective layer of oriented hybrid materials, also known as surface-anchored metal-organic frameworks (SurMOFs).

Investigation of the Photochromism of WO, TiO, and Composite WO-TiO Nanoparticles.

We report the synthesis of WO, TiO, and TiO-WO nanoparticles by a polyol route, with the objective of studying the influence of the preparation method on their photochromic properties. By combining transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and diffuse reflectance experiments, we show that low W concentrations and high ripening temperatures allow the preparation of WO nanoparticles with high photochromic efficiency. WO-TiO nanocomposites (NCs) prepared by the introduction of a TiO solution in a WO nanoparticle suspension exhibit a strong coloring photochromism, which is attributed to the TiO coating of the WO nanoparticles as it involves the formation of W-O-Ti oxo-bonds in place of W-ν defects.

Silver Nanowire-Based Transparent Electrodes for VO Thin Films with Electrochromic Properties.

The development of electrochromic systems, known for the modulation of their optical properties under an applied voltage, depends on the replacement of the state-of-the-art ITO (InO:Sn) transparent electrode (TE) as well as the improvement of electrochromic films. This study presents an innovative ITO-free electrochromic film architecture utilizing oxide-coated silver nanowire (AgNW) networks as a TE and VO as an electrochromic oxide layer. The TE was prepared by simple spray deposition of AgNWs that allowed for tuning different densities of the network and hence the resistance and transparency of the film.

Insight into the generation of near infra-red (NIR) absorbing species in electrochromic surface-anchored metal-organic frameworks.

Due to their versatility and easy processing, Surface-Anchored Metal-Organic Frameworks (SurMOFs) have gained interest in recent times as promising electrochromic thin films. Herein a step forward in their use and characterization was achieved thanks to the integration of {Zn(PDICl)} SurMOFs in a multi-layer electrochromic device (ECD), based on a membrane-like electrolyte. The optical and electrochemical properties of the ECD were fully characterized, revealing a two-step reduction process localized on the organic ligand and involving subsequent near infra-red (NIR) and cyan absorbing states, leading to optical modulation of the films.