The diversity of photonic crystal films color by changing of coating solvent and number of coating.

Abstract

The object of our research is to observe the expression of 1D lamellar photonic crystal color depending on different coating solvent (Propylene glycol monomethyl ether acetate (PGMEA), Tetrahydrofuran (THF)) and increase the number of coating. Color changes of photonic crystal would be reported through a simple method. 1D lamellar photonic crystal was made by the molecular weight of Poly Styrene-block-Poly-2-Vinyl Pyridine (52k-57k, 84K-69k, 102k-97k) in different coating solvent Tetrahydrofuran (THF) and Propylene glycol monomethyl ether acetate (PGMEA). The solvent was coated in two ways. One of the spin coating was performed once, and the other is a spin-coating twice. Then we accomplished annealing. Twelve different results was obtained through experiments. A variety of color expressions was analyzed through UV visible spectrometer.