Interference (communication)

Electrochromic devices

Intercalation (chemistry)

Metallurgy

Materials science

Reflector (photography)

Tungsten oxide

Layer (electronics)

Tungsten

Fabry–Pérot interferometer

Telecommunications

Electrochromism

Computer science

Inorganic chemistry

Wavelength

Physical chemistry

Physics

Nanotechnology

Optics

Chemistry

Electrode

Channel (broadcasting)

Light source

Optoelectronics

Nature Communications

Intercalation-based inorganic materials that change their colours upon ion insertion/extraction lay an important foundation for existing electrochromic technology. However, using only such inorganic electrochromic materials, it is very difficult to achieve the utmost goal of full-colour tunability for future electrochromic technology mainly due to the absence of structural flexibility. Herein, we demonstrate an ultracompact asymmetric Fabry-Perot (F-P) nanocavity-type electrochromic device formed by using partially reflective metal tungsten as the current collector and reflector layer simultaneously; this approach enables fairly close matching of the reflections at both interfaces of the WO 3 thin layer in device form, inducing a strong interference. Such an interference-enhanced device that is optically manipulated at the nanoscale displays various structural colours before coloration and, further, can change to other colours including blue, red, and yellow by changing the optical indexes (n, k) of the tungsten oxide layer through ion insertion.

Towards full-colour tunability of inorganic electrochromic devices using ultracompact fabry-perot nanocavities