Self-assembly of silica colloidal crystal thin films with tuneable structural colours over a wide visible spectrum

- Structurally coloured colloidal crystal films have been self-assembled from silica nanoparticles.
- The structural colour of the films covers a wide visible spectrum from red to violet.
- The silica particle size can be well controlled within the range of 207-350 nm.
- No purification and/or modification process are needed for the self-assembly.
- The structural colours can be tuned by the particle size or the viewing angle.