Fig. 3. Fabrication of enhanced PS photonic crystals with different carbonization of GQDs. (a) Photographs of PS/GQDs photonic crystal flakes by centrifugal sedimentation method. GQDs reaction time from left to right was 0, 3 hours, 5 hours and 7 hours. (b) Photographs of PS/GQDs photonic crystal films by drop-casting method. The scale bar is 2.5 mm. (c) Reflectance spectra of PS/GQDs photonic crystal films. (d) Corresponding normalized reflectance peak intensity of the PS/GQDs photonic crystals. (The size of PS nanoparticles was 214 nm. The various degrees of carbonization of GQDs were at the same concentration of 1 wt%.).
