Tunable colors from responsive 2D materials

Abstract

One of the long‐sought‐after goals in responsive material development is to generate and tune colors for advanced and emerging applications such as dynamic displays, light‐emitting diodes, lasers, smart windows, chromic fabrics, high‐security encryption, and visual sensors. Benefiting from the atomically thin nature as well as strong optical interaction, two‐dimensional (2D) materials can serve as color‐generating centers for both chemical pigment colors and physical interference colors in solution, gels, films, and matrix interface systems, to offer new promises for color science and applications. Concerning color tunability, 2D material systems have been demonstrated as one of the ideal responsive materials to achieve the desired goals, including the change of composition, layer thickness, strain, magic angle, and thermally/photically/chemically responsive, magnetically‐responsive, electrically‐responsive, mechanically‐responsive. This makes it an attractive prospect for device applications such as optoelectronics, displays, and nanomedicine. However, to the best of our knowledge, no comprehensive review has been reported specifically on color‐centered aspects of 2D materials. In this review, we highlight experimental approaches and related applications for tuning pigment colors, reflective structural colors, and transmissive interference colors, and we refine the challenges and propose opportunities in future studies for the further development of color science in the 2D material system. Eventually, it is anticipated that this review will serve as a resource and source of inspiration for scientists, as well as open up new avenues for the advancement of color science and related fields in responsive 2D material systems.

Rationally Integrating Charge-Transfer Cocrystal and Ni(II) Organometallics for Visualized Photo/Thermochromic Sensors

“…Thermochromic materials with unique thermoresponsive color-changing to environmental conditions or stimuli have received significant attention in both fundamental types of research studies and various applications, − such as energy harvesting/conservation, , information anticounterfeiting/encryption, − intelligent sensors, − and smart textiles. , For instance, vanadium dioxide with reversible metal-to-insulator transition displays controllable thermoresponsive absorption properties for color switching, which has been regarded as a prospective candidate for thermochromic smart windows . Nevertheless, thermochromic metallic oxides normally suffer from complicated designs, sophisticated fabrication techniques, or high switching temperatures, which severely hinder their practical application. , Owing to the tailored molecular structures and tunable physicochemical features, immense efforts have been devoted to developing organic thermochromic materials, , typically, crystal violet lactone materials with adjustable thermoresponsive temperature, by selecting a specific organic solvent .…”